Healer Class: Rune Master

[Lemuria]

But any class sucks to play while lagging lol. And can causes issues

This would be lag x1000 though. Having to perform a combination in order to cast a simple cure spell would make spellcasting slower, even if you eliminated spell timers. Can you imagine needing to cure bomb a paladin after a tank buster? "Sorry tank, Cure III is a 3-button combo!"

I'm exaggerating, of course, but even a single one-button Mudra shuriken takes longer to fire off than a cure spell you have at your beck and call. So, I have a suggestion for improving your idea. Instead of having forced combinations, make it more open. Firstly, allow your 'runic' spells to be cast singularly as normal. Then, introduce a 'combine' skill which allows you to queue up several runes in a row, which would activate a combination skill.

That way it won't get in the way of normal play, but it can still provide advantages all of its own.