Joe Mamma's page

Reading through all the Shifter talk made me realize for the first time that the way I built/played a (1e, "chained") Synthesis Summoner years back was probably very close in style to what some folks want from the theme/archetype (with the need for some heavy reskinning). The ability to pick and choose the features you want out of a pool of options (from attacks, to movement types, resistances, and even size), with evolution spells allowing you to temporarily modify those options on the fly.
It was a ton of fun to play and very flexible in and out of combat, and I leaned almost fully into the martial aspects of it. Of course the class and archetype were overtuned, and had the potential to overshadow teammates if one doesn't ignore large swaths of the chassis (the rest of the condensed spell list, summons, pounce + tens of natural attacks, etc.).
Too bad the 2e Summoner seems to have lost that flexibility, and the Synthesis build now looks like more of a hindrance than benefit.

What level range are you starting/looking at? If it's 8+, you might look at the Evangelist prestige class, where there are a few deities (Sivanah and the redeemed Noticula come to mind) that'll offer some spell-like Illusion abilities as you progress, while still keeping nearly all of your Slayer or Fighter progression.
Esoteric Knight is another PrC option for progressing both martial and magic abilities, but it'll require a dip into a psychic casting class first.

At 5th level Fighter, the Child of Acavna and Amaznen archetype will give Bloodrager casting (which include some delayed Illusion stuff).

Have to agree with what most other folks are leaning. Even though the Pally isn't one of my top classes, I've looked at building a PC without Divine Grace (Oath of Chastity/against Savagery, Gray paladin, Martyr, and Tortured Crusader to name a few). I've never had the want to make a Child of AnA; it felt like one of the weaker Fighter archetypes, which is saying a lot since all of my PCs end up having some casting options.

In a Wrath of the Righteous game, I built a Human Spirit Dancer VMC Bard. It was setup to throw out a silly number of buffs to the party in a single round, and tacking on a few Mythic levels ratcheted that up to the heavens. Due to party comp and play style, I was built to fill in as the party Face, Tank, secondary DPS, and Skill Monkey when needed; having the flexibility to shift on the fly was a nifty trick.

My favorite style is the Rogue (or Rogue-adjacent swashbuckling type, since the base class is often on the low end of power in many systems). While I never did the tropey stuff like stealing from the party / switching sides in a combat / prioritizing myself over others; I loved the benefits of high Dex (stealth, flashy acrobatics, decent AC) and trying to use a decent Int and Wis for off the wall shenanigans in and out of combat.

I've tried to get out of that shtick, but it's easy to fall back in to at least parts of it, and seemingly only really succeeding once. My Cleric (PF) took the madness domain for a touch of chaos to combats, but stayed pretty true to using debuffs, AoE control, and the occasional heal to keep the party running. I built a mythic Meduim (+VMC Bard) for "Wrath of the Righteous" that could buff teammates to the stratosphere while being an okay tank, but the game died early in the same book (4?) I brought her in. A pure Bladesinging Wizard (5e) became more of an arcane trickser in everything but name, dancing in and out of combat with quips to draw foes. And my current Warlock/Sorcerer multiclass (5e) built to bend the action economy to heal my allies, has became fond of illusion and enchantment magics to distract or misdirect instead to mitigate damage (and the need to heal).

I really like the Warrior Poet archetype for the Samurai, but between your archetype and Order, you have a few options in your build style.

It could also be worth a dip outside of the class into Fighter or another with early level bonus feats to stack a few more copies of Unconquerable Resolve or other feats. Would boost the HP gain per use, while potentially getting less daily uses of Resolve (and higher level Samurai class options, of course).

I had a silly build using a Samurai with most feats going into Unconquerable Resolve (can also be done with a Kinetic Knight, as they get the Resolve class feature at lvl 3). Every time you use Resolve, you also gain 1 temp HP per HD, stacking with the number of times you've taken the feat. So if you went crazy with it (probably not optimal...), at level 9 as a Human Samurai, you could have taken the feat 6 times, giving you 9(HD)×6(feats)=54 temp HP at a minimum of 5 times per day. At 20, you could have 10 uses that each give 20x11=220 HP.

Resolve can be used as a standard action to remove conditions, and more importantly as an immediate action when dropped below zero HP to stabilize yourself.

Toss in the Yojimbo archetype so you can use your Resolve feature on others, and/or the Headband of Deathless Devotion to boost Resolve by 2 class levels.

Depending on the level, I think a Reincarnated Druid would be a really fun reoccurring villian. By 6th they still have the various wildshape forms to run away when needed, summons to act as meatwalls, along with plenty of movement-imparing spells to frustrate the party.

At 5th, if the PCs finally manage to kill them, they come back to life (in a completely new and different body) after a day, and can sense where their former equipment (newly looted by the party) is located. Even if/when the players realize it's the same enemy they've killed 3 times, they can never be sure if the new friend they meet a few weeks later isn't carrying a grudge across multiple lives.

I believe party could technically not use any spells on day 1, start adventuring early/without resting on day 2, use up their available spells, rest/recover spells, and then burn through a second set of spells later in day 2.

Paladin (saves), Bard/Skald (buffs for you and your crew), or Occultist (w/Trappings of the Warrior panoply) are the 3 classes that jump out with that stat spread. It'll be tough regardless, but I'd assume starting stats are going to be tough for the party in general.
Good luck.

Pretty sure the Rogue is my "spirit animal", so to speak, regardless of game system. In my last few games I have tried to move away from that style (sneaky/sly/subtle, not the backstabbing/stealing from the party schtick), but each character did sort of migrate back that direction.
I'd love to try playing an Inquisitor, Vigilante or Occultist one of these days as a pseudo-Rogue, thanks to their customizability, but at this point my Pathfinder 1 options are limited to GMing. Some day, maybe.

2 feats will get an animal companion at level-3, with a third investment getting it fully leveled.

Nature Soul
Animal Ally
Boon Companion

Variant Multiclassing (VMC) into Druid would cost every 2nd feat (3rd, 7th, 11th), and would also provide a fully leveled companion (along with Wild Empathy and the Druidic Code).

Gaining a domain (via VMC Cleric or otherwise) and taking the Animal Domain will get them one at level-3, which again could be increased by Boon Companion.

There are at least a few more ways to get more restricted animal companions like those of Rangers or Cavaliers, but the above hopefully helps.

Pathfinder is a game you play with friends; have fun, and remember that the others at the table are there to have fun too (including the GM/DM),

3 attempts so far, zero successes. Will most likely keep on trying.

Made it to Book 4 of Wrath of the Righteous. GM was moving out of state, and the group fell apart about 4 months pre-emptively.

I GM'd to the end of Book 2 of Giantslayer, life intervened with a player couple and we haven't met back up since.

Ran a single session of Kingmaker as GM for my long-time gaming crew (who were basically new to PF, but not 3.x), no player drive to have a second session. Oh well, only way to many hours of prep work for that one, ha.

As ZZA mentions above, the Ghoran race may worth a look, along with using Bloodrager as the primary class. The Abberrant and Verdant bloodlines (with the Crossblooded archetype) may be close enough to be fun and workable.

Gunner Squire (Gunslinger)
Pack Mule (Fighter)
Weapon Bearer Squire (Fighter)
Combat Healer Squire (Paladin)

I'm sure there are a few others that can be molded to fit your specific theme, but the above are all magic-free (until 4th lvl for the Pally). Hopefully you can retrain some levels once you feel the character has grown into a true adventure/hero.

When in Book 3 of WotR, I was able to play a NPC the party had saved way back in Book 1 (adding class levels and filling out her background). I don't believe any of the other players realized who she was, unfortunately. Considering most of the original PCs that were around in Book 1 had died or left the party by that point, maybe it was simply appropriate role-playing.