[Endoperez]

I think the aura causes fatigue, with magic resistance negating the effect. The aura shouldn't hurt friendly units after the 3.10 patch.

With just 18 hp and protection 8, you the Shuten-doji could be kitted out but wouldn't probably fare that well. It is one of your two good leader-types, being able to lead 80 units, so you might recruit couple. Against heavy infantry, I guess they could be used to fatigue them. Depending on how much fatigue they cause and if you can position them well enough, they could even be used to effectively give attack bonuses to your troops against spesific targets - fatigue starts dropping attack and defense very quickly. That would be quite dangerous, though. Shuten-doji can survive a stray arrow, but they'd be quite vulnerable in melee without items, and aren't good enough for you to spend much on them.

Also, they can't use weapons or shields without losing their lifedrain. With weapon, they lose claw and lifedrain, with shield they lose just lifedrain and keep claw.