Merits Help

i have Heavenly Strike and Wind Blade at 5/5. now it says element dmg on both of them, so should i fully merit Avatar Magic ACC & ATT?

5/5 Magic attack is the best thing to 5/5 out of that category.
Physical attack/acc and magic acc don't have much of an impact especially at 90.

If you have decent skill over cap you will rarely resist on a merit BP.

Magic Attack it is! yeah i hardly get resisted. So should do Avatar Magic Attack ad just Avatar Attack then? be nice to see a stronger Mountain Buster from Titan on dolls in Aby Altep. Seems the other avatars are slacking behind in dmg vs merit bp attacks.

Honestly avatar attack has been shown to do very little. It does help, but not much. Avatar accuracy is probably the safest bet, unless you think you're capped in almost all cases then either go for avatar attack or avatar m.acc.

Most people do avatar m.atk & avatar acc. Personally, I went 10/10 physical and don't have any magic attack merits, but I use the merit BPs less than most people do I think. (Yes, I have 5/5 Heavenly Strike, Beyond/Ultimate/Minikin atmas, Pet:MAB+12 Shareevadi, etc... but even so, I don't find the magic ones to be that effective in the situations where it really matters.)