Skill A for +Hp -Res M.Grima

I am in the same doubt but with better IVs (+Atk -Spd, this one took revenge for my past +Spd -Atk).

You can make the usual bold fighter quick ripasta armor build, putting a breath skill on the A slot. If you want to keep him as EP unit, you can try stance A skills for +6 to a stat or +4 for two. Since yours is +Hp you can even consider Boost skills for a +6 on both phases if you meet the HP requirement.

if you want to keep vengeful fighter then close defense is probably the best out of those three. Fury is kinda counterproductive with his defenses because often the enemy will do no damage to him whatsoever but he will still take fury damage which can push him out of the VF range. If you have the possibility you can also give him a breath skill , which would guarantee an aether on every enemyphase or warding stance to patch up his res. For a budget option you can also use Svalinn shield so counter armor effective weapons

Fury is pretty good, if you have any stances, from halloween Dorcas perhaps, that would be better.