I’m looking at the old version and noticing the notation for spells that deal damage while being cast – designated as “per action” in Half Effect. Which means, making a defense (which results in a half effect) happens on a per casting-action basis; There’s no prolonged effect – you either avoid the damage or you don’t.
Well, these types of spells are all but non-existent in the book. Instead, there’s the Flare spell, which doesn’t deal any damage during casting, and then affects multiple targets with one damage die at the end of casting. There might be one or two others like this, but more pressing is the question: should the game have damage-over-time spells or all-at-once spells? Or possibly both?
Both types of spells offer the caster the ability to deal multiple dice of damage for a lower MP cost than casting multiple 1st-level spells. The first type allows choosing from just one or multiple targets, while the second allows the ability to catch opponents off-guard when you make multiple simultaneous attacks.
Including both types of spell is possible, but might not be necessary, especially in a light-weight, core rules system.