He is kind of right on the border of the reliable HP threshold. 50+ hits a lot more units and you can forget about triggering PP against abyssal or even most infernal PvE maps enemies with inflated stats. You would miss a lot of merged armor units which is what most of the arena "meta" continues to consist of and probably your intended ploy target.
A blessing or bonus ally boost would help, but I think in general you would be better off running it as a seal if you think it is going to help.