I am currently homebrewing alternative types of casters for D&D 5e, and mostly looking at making them unique through new ways of casting spells. My main objective is to keep them in line with the current casters and their strong points, without making the original ones irrelevant or underpowered in comparison (this is what I define as "balanced" in the context of this question).
I've refined one of those ways of casting, and am now under the process of balancing it. However, I am aware that spells and spellcasting in general can easily be abused or broken, and thus I am looking for feedback on the following ability.
For the context of the ability itself, it will either be the core feature of a new wizard-like full caster, or an ability directly granted to a wizard, either as a feature or a magic item. As such, you may evaluate this with a wizard's spell list, although if there are interesting things to point out with spells not in this spell list, I'd be glad to hear about them, in case I ever allow multiclassing.
Here is my current take on the ability which I've currently named Spell Melding (still haven't found a name I'm satisfied with, but that can wait) :
Spell Melding. Experimentation around spell-storing magic has given you the ability to hold a spell's harming potential, and inject it back into another spell later on.
When you cast a spell that inflicts damage, you can instead choose to store the spell's damaging aspect. You can only store one damaging aspect in this way, and storing another damaging aspect erases the currently stored aspect. Any component and spell slot used during the casting is consumed as usual, and the spell is considered as cast successfully.
When storing a damaging aspect, roll the damage of the spell as if you cast it normally. The damaging aspect retains the spell's final damage values after applying modifiers (outside of target-related modifiers such as weakness and resistance) and its damage types.
When you deal damage with a spell, you may inject your currently stored damaging aspect into the damage-dealing spell. The damage of the stored aspect is added to the current spell's total damage, and retains its original damage types. The stored aspect is consumed in the process.
A stored aspect cannot be used on the same round it was stored. Additionally, a stored aspect vanishes after being stored for 1 minute.
The description is quite long, as I tried to limit any unintended interaction that could break everything. The basic idea behind this feature is to give the ability to "hold" onto the damage of a spell, then release it alongside another spell later in the combat, allowing to deal large amounts of damage in a single attack.
The main goal of this ability is to give an alternative, more risky way to use spells, but with much larger bursts of damage. It makes you use your action on a turn to technically do "nothing", but allows a much larger damage output on your next turn, which depends on the resources you've spent during your previous turn.
Here are the main concerns I currently have about this feature :
- Combat can be fairly short, no more than a few rounds, so this feature may be too slow to be fully taken advantage of.
- There may be ways to abuse how this feature is written in order to deal damage much higher than intended.
In the situation where this feature would be slightly unbalanced, but not to the point of having to totally reworking it, I have the following solutions :
- If too weak, instead of entirely consuming the stored damaging aspect, only half of it could be consumed, while keeping the full damage bonus applied. This would result in getting 1.5 times your original stored aspect's value, over the course of 3 spell castings.
- If too strong, injecting the stored aspect into a spell may require a bonus action, instead of being free in the action economy.
Is this ability balanced for a wizard-like full caster, when compared to the current full casters?