I know a lot of people think you should not multi-class with inquisitor because of all the awesome things high level inquisitors get especially greater bane, but I'm not all that interested in the high level spells or stalwart class features. I built this inquisitor of Cayden Cailean with a flanking rapier in mind, and took the best combat/teamwork feats to help get the most out of it, but the 3/4 BAB makes sad, when I have a Bloodrager and a Fighter on my team.
Currently our party are all 9th level and I was thinking to begin my multi-class at 10th level so that the other parts of my judgments can go up by 1 and the smiting can add adamantine. But I was wondering what yall thought of dipping into ranger levels, or are there other classes I should be considering.
Well, since rangers only start to really shine once you get access to combat style feats without having to take the prerequisites, I'd warn away from that since it would only come online at a very high level. If you want more combat utility, you could take a level of anything that gives you channel energy, take Alignment Channel (evil), and become a Holy Vindicator. I'm not really sure how good this would end up being, but it would bump your bab and give you some nice bonuses on top of your judgements and bane in the form of Stigmata. It also buffs your hp and advances spellcasting at some levels.
Magistrate Vargri is a PFS Bard-1/Inquisitor-X. Brawler is a great foundation class for any martial character. Level 1 Brawler's Martial Flexibility is exceptionally useful, such that it has it's own guide.
Like you, Vargri is not interested in high level play. His build came together at 5th level, when he gained Spring Attack and access to Whirlwind Attack. Martial flexibility is great, and can be worth losing out on one Inquisitor level.
Vargri often takes Tandem Trip as his Teamwork Feat. This makes him supremely effective at tripping when tripping applies.
If you are currently 9th level I’d wait to multi class until after 12th. Your bab progessses at 1/ level at 10th,11th, and 12th level (same rate as a ranger). Are you having trouble hitting?
If You must do it sooner, I’d go slayer (more flexible then ranger) or fighter with the mutagen warrior archetype and stack it with the martial master archetype. You gain a mutagen (+4 to str, dex, or con) and the ability to switch out feats on the fly like a brawler.
If you're not interested in the higher level spells, I think you're playing the wrong class (just my guess if you're jealous of the Bloodrager and Fighter). The higher level spells especially give you huge benefits in combat (and many spells outside of combat). You already have Bane, two Judgments, and multiple buffing spells, and at level 10 you get 4th level spells like Divine Power, which is huge (if you don't have someone consistently casting Haste on you...if you do then it's not much better than Divine Favor). Not to mention the teamwork feats. You should DEFINITELY be keeping close to the Fighter and Bloodrager and offering much better out of combat support than they can.
Giving up spells like Divine Power, Righteous Might, Greater Invisibility, etc and giving up Greater Bane...in exchange for at best
a mutagen and one extra combat feat aren't even close to a fair exchange...
What makes the inquisitor powerful is synergy. They can get a lot of smaller bonuses that all stack together. I suspect that your spell selection may be focused on the wrong Things. You should have enough combat buffs to get your chance to hit to be about the same as a full BAB class. Divine Power like others have said is one of the go to spells for an inquisitor.
One spell that a lot of people overlook is heroism. It is a long lasting buff that gives you a +2 on just about everything you do.
An inquisitors spells should not be direct combat spells, rather they should be buffs and utility. A fully buffed inquisitor is one of the most deadly combatants in the game. The problem many people have is they want to constantly match the full martials. What an inquisitor does best is to wait until they can prepare and then take out the really tough opponent. Essentially you are a divine assassin.
In all honesty it sounds like you would have had more fun with another class. Multiclassing this late is probably only going to make matters worse. You have too much invested in inquisitor and the other martial classes are going to start getting their late game abilities. If you multiclass you will not get any powerful abilities.
I haven't though about looking into prestige classes thanks for the idea, but having access to 4th level spells and taking those 2 spells (divine favor and maybe Judgment light, not decided on the 2nd spell) is why I wanted to wait till after 10th level. So 11th level is when I want to start another class, as for greater bane I can still get it with a bane baldric plus the extra 5 rounds of bane is handy.
Although your right Mysterious Stranger, a fully buffed inquisitor is really powerful(swift judgments and bane, buffs that last mins/lvl) it takes a couple of rounds to get there. Much like Batman, given a little but of time to prepare he becomes and unstoppable force, but in a do or die quick thinking scenario with no time to prepare I'd want to at least be there to help than stand back for a second to get ready.