So I was playing around with the evolutionist to see what I could break and I ended up writing this guy. I took an hour or so to do it (most of that being evolution choice and formatting), so it's not finished, but I found that the raw potency that this class offers is incredible--specifically the at-will casting you can pick up. I recommend imposing per-encounter limits of some kind instead of per-day, with harsher scaling, and implementing some sort of buff-persisting evolution for SLAs so characters can get persistent effects instead of racking up and ability and using it at-will every time the duration expires..
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Orc Evolutionist 6, Level 6, Init +1, HP 48/48, Speed 30
AC 17, Touch 11, Flat-footed 16, Fort +6, Ref +5, Will +3, Base Attack Bonus 6/1
4 Claws +14 (1d4+3, x2)
Bite (Primary Weapon) +14/+9 (1d8+9, x2)
Chain Shirt (+4 Armor, +1 Dex), +2 Natural
Abilities Str 22, Dex 12, Con 14, Int 11, Wis 8, Cha 6
You make 6 attacks in a full attack, each dealing ~10 damage plus 1d3 Wisdom. You have pounce, at-will wraithstrike, and at-will invisibility. Go to town.