What to do with Ophelia and Myrrh

So I summoned on the Mythic Banner with 55 orbs and got quite a bit. 2 Ophelia (+Hp, -Spd and +Atk, -Res), Halloween Myrrh (+Res, -Def) and Brave Lyn (-Spd or something bad). I foddered the -Spd Ophelia for her Rally Up Atk+. However, I am not sure what to do with the other Ophelia and Myrrh.

For Ophelia, I already have a +Atk, -Hp one with Special Spiral inherited. Should I merge into the -Res one, merge into the -Hp one or fodder her Rally Up Atk+?

As for Halloween Myrrh, my current ones is +Atk, -Hp and am unsure if I should use the second one as a merge or fodder for Vengeful Fighter or Armor March.

Merge Ophelia as much as possible

You never know when enemy’s Megatank will survive with 1or 2hp and kill ophelia because you didn’t merge your Ophelia

My mega tank often barely survive non merge or low merge Ophelia and kill her in counter

I’d say merge at least one Ophelia into the one you already have. As for fodder, ask yourself: Is there anyone who actually needs said skills right now? Unless you’re into high tier arena, the rally up may not really be needed, and if you don’t use armors much than Myrrh could be kept too. There both good units at least.