Well I would say it could go either way, on the one side, if it's for your merc you prob should have gone for eth, but on the other, perf ed is hawt. I would actually say you got an ok deal now because you could also use it on a barb if you made/have one.
a2 mercs are good, barb mercs strike more often and have more life and higher base def, down side is that they cant use a shield but they can use armors that req higher str
only worries are him getting cursed with im, just tele back and wait for it to wear off or find a well
my sorc can tank a little with es, fa, ill make a cta and another spirit mon for her soon (switch)