Party role advice desperately needed

[Digitalfruitz]

So me and my friends are playing a semi-evil political thief type game in a homebrew pathfinder setting we made. I need help with my character, Here is what the party has so far:

Dal, the Tiefling Investigator--> specialized in being a face, minor support

Willup, the Grippli Rogue--> two weapon fighting rogue, mainly a skill monkey/melee DPS

Tip, the Gnome Pyrokineticist--> ranged damage, ranged damage, and ranged damage

Squeebok, the Wayang Alchemist-> specialized in using poisons to do debuffs and range damage

Chloe, the Ratfolk Witch-> specialized in debuffs and CC

I know that I want my character I be a dhampir, and that I want him to be fairly wise, and I realize I will need to be a tank. But the problem is I don't want to play a character in heavy armor. Any help is appreciated

[Florian]

If it´s semi-evil, then an Antipaladin should fit. One level dip into oracle to get CHA instead of Sex to AC and you can immediately go for light armor and still be a descent, self-healing (damper and touch of corruption) frontliner.

[Digitalfruitz]

See the problem is that I want my character to be lawful so I can always try to make the party more cohesive

[Footman]

How about a Dex based Cleric or Oracle? Oracle works better here since you have a better synergy with the Cha as Casting Stat.
If you go the Cleric Route, you could also be a Lawful Neutral Cleric of Asmodeus, who is more of a "playing by the Rules" Typ, then Evil.
Just Take Weapon Finesse at First Lvl, and Dervish Dance at Third Lvl, (don't forget to put those 2 Ranks into Performance "Dance"), and you are good to go. If you channel negative Energy, you can even heal yourself with that. You could also start a Necromancer Career, by Lvl 3 if you want, (or Lvl 1 if you take the Undead Master Archetype), to get some Undead as Meatshields for your squishy Friends.

Since you want to be Wise, i really Advise the Cleric, your Ability Scores will be a bit low, but you can always Buff yourself up, if you want to Fight in Meele.
Other than that, i think the Warpriest is a good option, if you want to be more Martial than the Cleric, he strikes a nice middle ground.

I hope i could help you!

[Florian]

See the problem is that I want my character to be lawful so I can always try to make the party more cohesive

Use the Tyrant archetype.