Dawnflower Dervish Bard.
Dex based level 1 and has skills with a CHA focus.
This calls a bit for a melee frontliner. DEX based can narrow it down a chunk. Automatically I think of Swashbuckler. That has high CHA and DEX along with decent skill points. Slayer is pretty straightforward and fun as well.
If he wants DEX to damage, you'll need fencing grace, slashing grace, dervish dance, three levels of unchained rogue, or some other things I can't really remember. This calls a bit for full BAB classes.
I would probably go for a Daring Champion Cavalier, it trades out all the mount stuff for some swashbuckler tricks. Good skill points, high Charisma, and easy DEX to damage options. There is also tactician. Some good teamwork feats out there but if that's a bit too tricky straight Swashbuckler can work. Maybe even a dip plus one of the tactician-less archetypes.
Maybe take a look at that one Mesmerist Archetype. Something fencer that gets some feinting boosts and melee treats.
What are the other builds like? I can see the Rogue being a striker and flankmate. The Oracle looks like they'll be doing most of the party buffs, but do they have offensive spells and do they fight? Does the alchemist rely on bombs or turn into a mutagen behemoth? If the party has melee covered I might go for a Skald or Bard. They get good skills and Charisma, and can provide excellent whole-party buffs.
