Spells galore

Catapult: ranged spell that launches its target straight up into the air upon hit

Dimension warp: teleport to the nether if in overworld, teleport to overworld if in nether (do nothing in the end maybe?)

Life leach: low damage ranged spell that heals you a small amount when it hits

Arcane deflection: when an entity hits you they get knocked away (you could add levels to this where they gain negative effects or damage when they get knocked away)

Nimble Feet: gain speed and a new potion effect Nimble feet (or rename to whatever you want). Nimble feet gives you a chance to passively dodge attacks that would have hit you (done by using global trigger 'before entity hurt' and cancelling global trigger)

Withdrawing Tortoise: gain resistance 3 and 4 absorption hearts, but also gain slowness 4 and weakness 1 (obviously tweaking the effects to balance to your liking)

Chain Lightning: Ranged attack that if hit, will cause lightning to strike a target, then if any other targets are in range choose a random one to strike with lightning, repeating up to 4 times

Aura of Slowness: slow all mobs in an area around you

Explosive Tendencies: causes an explosion at all entities between 2 and 7 blocks away from you

Cow of Doom: Ranged spell that shoots a cow, deals high physical damage, if it kills its target summon a cow in its place (obviously this is a silly one but i like it)

Reapers Deal: gives a potion effect that if you would die while the effect is active instead be put on 5 hearts with 4 absorption hearts and the effect is removed

Druid Pact: gives strength, resistance and regeneration to all dogs within an area (perhaps upgraded version gives weakness and slowness to all aggressive mobs in an that area also)