@NautArch The 'many dice' should not be only in a nova or rarely used ability. It doesn't matter if its a caster, a melee attacker or whatever, just that you throw a lot of dice all the time, all throughout the adventure day.
> A good answer has a build that is viable. It doesn't need to be CharOp levels of optimised, but it shouldn't be a burden on the party either. Therefore, self-inflicted disadvantage (as mentioned in comments) is not in the solution space, as well as similar self-harming methods, unless they actually improve the combat capabilities of the character.