... Create spells

Spells doesn't use Data Tables. To make a new spell, you need to inherit from the BP_Spell class, and override few functions.

Since V2, spells inherit from Actor instead of Object. I take the opportunity to add several components to gives specific behaviors to spells. I call those components "Decorators".

I have also made multiple templates for spells. It can inspire you for your own spells.

Decals :

To show the area of effect of a spell, I use decals. spell decals is represented by the BP_SpellDecal class.

You need to override the UpdateDecal() function in your own decals. You also have access to the spell which is linked to this decal (the spell which is currently casted). Remember that this spell that a ref to it's owning SpellUser component, you might need this ref.

Have a look on the BP_DefaultSpellDecal to see an example of use.