I thought it'd be cool to use the Evoker magic spells when I saw it first use it. So I continued to think and wonder of what other spells the player could use in the idea mod and here is what I came up with:
Lightning strike: You can use a lot of "mana" so to speak to strike lightning on opponents like how channeling does in thunderstorms.
Insomnia's Conjure: Depending on how much power you use you can summon phantoms to spell doom on your enemies. Only usable at night.
Ring of Fire: Cast multiple blaze shots in a ring. Similar to how the Hovering inferno was supposed to inflict on you in the community-supported contest.
Wither's Spine: Once the Wither is defeated, you can copy the attacks it showered on you with the pelting of explosive skulls.
Draining: Use this on any mob to inflict damage on them when faced.
Magic Protection: Like Daruk's Protection from Breath of the Wild, you can purely shield yourself from attacks at will. But only with a limited number of uses.
Control of the Dead: Pretty self-explanatory. You can lift the dead to fight for you.