Between his Lifesteal and 1-turn ATK boost, Alliance General is at his best supporting a team of physical damagers. From what I understand he's currently far better at PVE than PVP.
I heard he's fun with a Strike Talisman set (mostly Fierce subtype is probably best) so he can steal more Power and Fury from opponents.
I don't have these though, so I settle with playing to his strengths and giving him 6 Energy Overwhelming.
Although I've had this guy since October, I've actually never fielded him, be it in PVE or PVP
BTW, a while back we had a discussion thread on who he was based off of in RL.
Stalin did show up, but our more likely theories were either Harold Alexander or Adrian Carton De Wiart.