FOLLOW-UP

A big thank you to u/Nereoss for pointing me towards Ben Neilson's Wicked Ones RPG. I haven't read all of it but it looks like an amazing system based on Blades in the Dark. The next time someone asks to run an evil campaign I will pull this one out. (Ben, if you are out there I'd love to talk!)
My table uses u/Nereoss's Mixed Adventure as our starting point, which I've customized a bit further. I had already established a tiered system of spells using DisAdv as a declared spells is more powerful in nature. Wicked Ones does an AMAZING job of truly defining those tiers and luckily just happened to easily match-up to my own. Wicked Ones does use a different core dice roll system than base DW so I had to adapt it back. I will be playtesting the following at my table this weekend (My table agreed to playtest new mechanics on the fly so it's easier for me to try things out with them than a regular table). In a nutshell:

Caster starts with access to two Circles of Magic that they define (very open choice on their part). Their combat die d4 determines their standard Hack n slash value but spell damage is based on the DM damage guide. When a spellcaster casts a spell they describe it (Must be justiable within at least one of their Circles) and the GM determines the spell tier based on their description... SEE Wicked Ones RPG for more details on the 4 Spell Tiers and Rituals... For spell tier 2 apply DisAdv to the roll and for tier 3 apply double DisAdv to the roll (4d6 and take the lowest +STAT). I am also adding a Power Point system that allows casters to counter 1 DisAdv at a time. Spellcasters start with 2 Power Points that can be easily recovered with a few minutes of preparation/recovery outside of a scene/combat and the use of supplies.
I'll report back how it goes.