
Megistone |

Yeah, if the fighter is melee your front line is probably already covered (there's the Eidolon too).
A ranged would be fine, and arcane magic is never too much.
I would consider: Bard (arcane magic, very good support, you can make him an archer if you want), Wizard (9 level prepared arcane caster) or bow Ranger (very good at range, tough and useful outside combat).

Gavmania |

You really need to give more detail; for example, do the existing characters have any archetypes, and what role do they take in combat?
For example, a vanilla summoner can provide decent buffs and extra actions via his eidolon, a master summoner provides battlefield control and a synthesist summoner is a good front-liner (if you build him that way). The Fighter and Paladin could be Melee types or archers.
Finally, does the party need a skill monkey or do you have all the skills covered between you?

Useless |

Thanks for the advices, but Gavmania is right, i must give more infos about:
- The Cleric is an Holy Vindicator, combat role--> Heal, Buff himself, Critical Damage
- The Paladin (no archetypes) provide a nice damage and it's our main tank when the eidolon is away
- The Fighter (i don't know really much about his build) uses a whip, doesn't seems to provide incredible damage
- The Summoner uses his eidolon and buff when possible, when not summon lots of minions to use for whatever fight, tank or heal
I think skills are covered, paladin and cleric have good perception, spellcraft is covered by summoner and cleric, disable device by the fighter(i said i don't know much about him) and mainly by the eidolon.

Useless |

Well lemme say that usually the Eidolon damage is crazy, as the paladin's one.
The GM encounters are usually very hard (AC very high, nice numbers of attacks and criticals, which costed me already some PCs) but the party seems shut down them very easily, even if i should say, a thing which is sure is that those powerful monsters always get someone down, if not dead.
This last Big Badass Evil we faced (after defeating a Dracolich without rest) was a caster, some kind of necromancer, killed me and almost killed the fighter, and killed a powerful NPC, caster aswell.

Chromantic Durgon <3 |

Yeah to be honest I'm not convinced you need another damage focused character.
I'd go control, any 9th arcane or psychic caster would be nifty, if your not into that I'd probably suggest a bard or an alchemist, they don't have the control options of the full casters but they can buff fairly well and differently to the summoner. Alchemist can sort of control as well.

Blave |

What level are you?
I'd go with some kind of bard. Lots of skills and knowledge are very useful. My favorite support-build is combining sound striker and dirge bard focused on buffs and enchantments. Dirge bard gets rid of the largest group of enchantment immunities (undead) and sound striker provides some on demand damage should you need it.
Or just a regular bard build as archer. With Arcane Strike, Good Hope and Inspire Courage, bards are actually quite decent at archery.
Other than that, any kind of level 9 caster focused on support and crowd/battlefield control should improve the party's odds of survival. Wizard, Sorcerer, Druid, Arcanist... Even a caster-cleric or oracle could work.

TarkXT |

With all that meat Ibday go wizard, bard or arcanist and work support/control.
You can boost numbers and improve positioning opportunities drastically. Your group shouldnt be hurting for damage so grant more opportunities to apply it. Buffs to increase attack, battlefield control to isolate targets. You can spare the summoner a lot of spells if you work to coordinate and enhance the group as a whole.

Useless |

Party currently level: 12th-13th
As said skills are mostly covered by summoner, cleric and eidolon; summoner is especially good in knowledge ones.
Well about the campaign, i think this is the first time we meet an undead. This adventure is very different and propose different encounters everytime.
The PC who just died was a sorcerer, and lemme say even having 29CHA seems not enough to work.. yeah some fights ended very fast thanks to me, but just some, in any other fight i fell behind and been almost useless.

The Steel Refrain |

I like the idea of a Bard, as others have suggested, to act as a 'force multiplier' for the rest of your group, while also having some clutch spells.
Maybe consider Arrowsong Minstrel so you can do your thing from the back whilst shooting arrows. Tuned Bowstring is an obvious choice for magic items in that case.
I've wondered how that archetype might combine with the Arcane Archer prestige class, given the earlier-than-usual access you can get because of this line from the archetype: "In addition, for the purpose of meeting the requirements of combat feats and prestige classes, an Arrowsong minstrel treats her bard level as her base attack bonus (in addition to base attack bonuses gained from other classes and Hit Dice)."
Because of that, you could conceivably get into Arcane Archer after just 6 levels of Arrowsong Minstrel Bard. The new Prestigious Spellcaster feat also helps offset the otherwise reduced spellcasting of the PrC. I haven't worked up a build, but I think it could be pretty fun.

Inlaa |

Bard would work well, as others have said. Inspire Courage will work wonders with this party. Heroism, Gallant Inspiration, and Blur are all amazing early spells. You get great fear spells at higher levels, and you get various means of bolstering your team. It's good.
But if you want to play a Sorcerer or Wizard again, go for straight-up control: grease, web, force wall, black tentacles, dominate... At higher levels, a well placed Wall of Force + Cloudkill can end certain encounters right off the bat. You also get buff spells like Heroism, Stoneskin (and its mass version), Mage Armor, etc.
Focus less on blasting and more on controlling the battlefield and providing your allies with buffs that last throughout the adventuring day.
EDIT: Basically, consider spells that don't give the enemy a saving throw. Again, Force Wall + Cloudkill can work wonders. Heck, Forcewall or Wall of Stone in general works wonders: you're literally able to cut the enemy's team in half by providing a huge barrier they have to get through somehow to proceed.

Useless |

I can see some nice advices here, i've understood that to face my GM effectively i should avoid save or suck spells (which sadly i love to use, but the monsters we're facing are hard to get down).
As battlefield control, are my only choices wizard, sorcerer and bard?
I never played a bard, i come from D&D 3.5 where bards were useless, cuz underpowered.

Inlaa |

Yes, the Pathfinder Bard is better, but the 3.5 bard was basically a solid 5th man to any given group and could stand behind the Fighter with a longspear while singing his songs. Or could use a ranged weapon. He was better off than the Fighter and Rogue at the very least (though that doesn't say much).
...Not to mention various abilities that were useful at the right time, like Counter Song and what have you. And remember: perform (oratory) or perform (comedy) or perform (sing) or even perform (dance) all could be used by the bard in lieu of an instrument, if memory serves. You might train in an instrument to use a magical one - but generally speaking, it worked just fine to provide your teammates with a bonus to attack and damage while wading on into the fray right with them.
Again, people just didn't understand how to play them. Bards were good. Just misunderstood.
...oh God bards are emo.
EDIT: Also, feats like Song of the Heart and others could make Bards even better at inspire courage. I think there were spells, too? I forget.
EDIT 2: An example of what a bard in 3.5 might do before battles: pre-buff before fights (Heroism and the like with long durations are noteworthy), carry useful wands, use skills where useful.
In a fight: Enter combat wielding weapon. Open with Inspire Courage, then immediately stop performing it (as it takes a standard action to maintain) with the performance lasting for 5 rounds after you sing. This provides your +whatever bonus to everyone for 6 rounds, basically. Then start fighting and casting spells when necessary, like a regular character would. Don't pluck harp strings all day; shout some inspiring words and KICK SOME FREAKING ASS!
Or be a Stormsinger and fuk da poleese! Seriously, dealing damage with your Perform skill opens up a ton of options if you can minmax it right. 1d20+CHA+ranks+whateverbonusesyoucanget=potentially a lot of damage with your songs.
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Ahem. Sorry about that. Anyway:
No, those aren't your only choices. They're pretty simple and straightforward choices, but not the only ones.
Really, if you do the right amount of digging, most 9th level spellcasters will work fine. A Cleric can be designed to be a control Cleric, maxing Wisdom for powerful spells, if you choose the right domains. A Samsaran with Mystic Past Life and some shenanigans I forget can get virtually any spell in the game with a little system mastery. Witches make amazing debuffers, and so can effectively control the battlefield that way.
Heck, there's even martial forms of battlefield control, limited though they might be. IIRC, there was a build with the Orc Fighter archetype Dirty Fighter + Lore Warden that managed to get Whirlwind Attacks that also dirty tricked enemies, disabling whole groups of mooks at once. But that, again, takes some serious system mastery to pull off (and won't work in every fight).

Megistone |

I could be wrong, but maybe your DM didn't like your save-or-suck spells shutting down encounters with a single action, and decided to up the defences of boss enemies quite a bit.
So, I would avoid going that route again. Witch was a good suggestion, but if hexes are not going to be effective during the important fights, maybe it's not the right choice.
If you still want to go full caster, maybe change your selection of spells so that you don't exert your control targeting enemies directly: walls and pits can't be denied.

Useless |

Thanks all for your suggestions.
Lets say i'm not worried about RP, is something i can get very easily, and i've no limits to what i could RP, especially related to the class or race.
As Megistone says my way to shut down too easily and encounter could have been for sure an imput to improve encounters, but not the only reason; as far as i can remember encounters were always very hard to face.
But yeah, lets say that even if i try to empower my DCs, they're not high enough, cuz i'm not lucky with dices and the monsters we face have usually nice stats and saving throws.
My only limitation is that i would like to play a small race, possibly a gnome, but i don't want to play an unoptimized character, so i'm taking advices on what fits better the party.

Inlaa |

Gnomes make terrific bards. I'm playing a Gnome Archivist (bard archetype) in an Emerald Spire game right now, and suffice it to say that he's freaking fun. Bards get great access to spells, and gnomes can get 3 1st level SLAs at level 1 with no real problem. It's awesome.
The long and short of it is I have a great stealth score by being small, I have Monkeyfish as an SLA (giving me a tactical advantage / advantage as a scout), and I also have Grease and Silent Image as SLAs (both of which have amazing utility), this from two alternate racial traits (Fey Magic and Faerie Dragon Magic, and yes, you can get both). Not to mention that I have some useful cantrip SLAs from the same traits (Create Water, Guidance, Purify Food and Drink, Ghost Sound). To top it off, gnomes have a bonus to CHA, and their extra CON never hurts. They also have a racial bonus to casting illusion spells (which Faerie Dragon Magic still has) and can get gnome-specific feats to improve illusions.
Overall, a gnomish bard, wizard, or sorcerer is a solid choice for group spellcaster. It's small, too, and if you prefer Sorcerer or Bard to Wizard, then the CHA bonus and the strong illusion focus can be great.
Also consider that there ARE some kickass illusion spells available to bards and wizards, such as...
Blur (buff), Mirror Image (self-buff), Wall of Nausea (makes enemies unable to take actions for 1 round), Vision of Hell (useful if you like fear-based spells), Greater Invisibility (rogue's best friend), the various Image spells for utility, Simalcrum... If you can ramp up your save DC, Phantasmal Killer and Weird are both "you save or you die" spells (albeit with two saves each). The Shadow spells (like Shadow Evocation) are super flexible, and potentially allow a Bard to cast Sorcerer/Wizard spells they otherwise never could. You also have means of duping divination, and again: TONS of utility.
Suffice it to say that while Illusion is far from the only spell school you'll use, gnomes being so good at it makes it a strong reason to play a gnome caster over a halfling one if you want to be small.

Useless |

Thanks again for answers!
I don't know honestly about bard, seems using mostly illusion and charm spells, two schools i don't like very much.
For the flavour, surely bard would be my class, so is there a way to use SoS spells on a bard?
About the fighter he isn't grappling nor tripping, i don't know honestly why he fights with a whip.
What about a necromancer-scythe gish? would be possible, or due to the small size would suck in any case?
Something like Polymorph or shapechange? Something focusing on AoO?

Inlaa |

bards are meh their class abilities give all moral bonuses so they dont stack with their good spells which is bad synergy
Inspire courage only gives a moral bonus to saves, the bonus for attack and damage is a competence bonus.
And moreover, the Archivist grants an Insight bonus instead of a Morale or Competence bonus. So if I'm an Archivist, I can use Naturalist to grant AC and Attack (insight), Heroism to boost attack (morale), and Gallant Inspiration to boost someone's attack bonus in a pinch (competence), all by level 4. It's not bad.