I don't know if I'm missing something in the nodes but Corvus is taking shock damage with Glaive charges. Also I think fisticuffs is taking true strike out?
The likely explanation is that Corvus is immune to the damage from shock debuffs but that is a passive effect causing the damage. Fisticuffs prevents buffs and debuff from appyling and truestrike is a buff.
Comments
*It is avoidable as it only triggers when you have activated buffs prior to ultron using a special.