Haltro said:
Simple question, Genbu's Kabuto or Arhat's Jinpachi? Situation would mostly be campaign but for tanking some other things as well.
Campaign, probably kabuto for the normal targets (NMs aside), but the damage decrease would be so minimal to the point where you'd be better off with an evasion set anyways.
The moment something hits for about 150~ base on you with defense gear aside, is when physical reduction is pretty much the clear cut winner.
supOh, and yes: Only swap it on when you're vulnerable, via Third Eye being down. That, or if you know for a fact there's a heavy-hitting area of effect move coming your way (Wind Shear from Vulpangue, example).