The stats:
40%+ Crit Chance to abuse Chaos Marquee;
30%+ Meter Gain to quickly charge Blockbusters in conjunction with Haste from Dark transmutation;
40-50% Defence to survive, get some Armor stacks from Water transmutation;
30-50% Piercing to deal with well-equipped Defence fighters;
Everything else into Attack;
If your combos are built around Special Moves, Special Cooldown of 30%+ is useful;
Crit Damage and Elemental Advantage can also be useful.
The skills:
Well, make a setup that is comfortable for you. Check some good combos on wiki or Youtube or invent your personal killer sequence. I usually say that Bandwagon Rushdown is a must because of Hex, but LSDouble can apply Hex by Light Transmutation, so BWRD becomes non-essential. Flesh Step is kinda useless; Taunt is too risky, and you get a lot of buffs just by blocking. Burst can save you sometimes, but essentially it's a loss of potential damage from attacking skills.