I was about to convert shadow bolts for DnD 5e, but shadow evocation does not exist for DnD 5e! Let’s fix that!
Casting Time: 1 action
Range: see text
Components: see text
Duration: see text
You pull concentrated shadow from the plane of negative energy and throw it with your will as an imposter evocation spell. When you cast this spell, choose an evocation spell of level 4 or lower. This spell mimics that spell cast at the lowest level spell slot it is able, except the spell is now disbelieved with a Will saving throw instead of either a different saving throw or spell attack roll. If the original spell required multiple attacks or saves such as magic missile or scorching ray , each attack requires its own save.
At higher levels: When you cast this spell using a spell slot of 6th level or higher, you may choose to increase the effective level of the copied spell by one or choose to cast a one level higher evocation spell for each slot level above 5th.