Champions of Conte

If you save up your units, yes you can have willpower and double edge. I haven't bothered....

Good setup:

Offense: (+10.5% crit rate, +52% crit dmg)
5 - precision
5 - Cruelty
1 - in all prereqs

Defense: (50% to resist block break)
5 - Stand your ground
1 or 4 - Perfect block
1 - in all pre-reqs
Optional: 3 salve, 3 recovery. (I haven't bothered yet)

Utility:
2 or 3 - dexterity (+20-33% increase in next attacks crit rate)
3 - pretrify
3 - pacify
3 - stupify
2 - Parry (stun duration increases with perfect block chance)
1 - pre-reqs


Do the offense first and use the stony cores for that. I did it without spending $0.01. Just save units from arena milestones, arena crystals, and completion/exploration awards.
FYI - always open arena crystals in batches of 10,20, or 30. If you open 10 at a time (20K battle chips), and press the open button, you will always get 15-75 units.