Micaiah

I mean... if you're bored of using Deathblow 3 + Moonbow, then don't use it.

Although I have a feeling you'll run into a similar issue with using LnD + Glimmer, but whatever works works.

Only thing is that Kagerochart, and most other battle simulators for FEH are somewhat misleading if you're trying to see what's "better" since you have to manually input "proper" (AKA Commonly used) builds for each and every character.

But, again, if you feel like it's worth it then go for it.

The damage calculator is honestly quite unreliable now, so if that's all you're basing your decision on then my answer would be no since destroying her Resistance is not ideal and the only match ups 28 - 33 Speed changes (Speed usually being the main factor to more wins on the damage calc) are probably against Armours (not counting red), Dragons, and non-meta threats who will OHKO her with DC / Lightning Breath or simply not used at all.

If you're bored with the set you're running than it's fine trying things out, but make sure you have some solid reasoning in your mind for doing so.

I also agree with the other dudes. Because for me, beside destroying those cav and armor unit, she also good for tanking those magic. So -5 res would be not worth it

Don’t do it! I recently pulled a +res -def Micaiah (my 2nd, merged the first into her) and her resistance is insane! 42 Resistance and distant defence 3 walls even green mages. So don’t threaten her resistance because you’ll miss it.