how do you use splats?

i think things like chainlighting, mana burn or whatever beams use splats, but what exactly tells an attack or spell to use the splats.

i want to be able to make a unit shoot different colors of lightning other than blue, or have an attack that looks like life/mana drain.

is it possible to make a mana/life drain target multiple targets instead of one. or make it work like immolation so that it drain every target next to it and a also have that beam thing?

how do you make a spell like shockwave explode like stampede when it collides with a target?

is it possible to change the way a spell is used to target something instead of basing it off of other spells?

how do you add splash to a spell that doesnt have it

i guess no one knows anything