You're thinking of it in terms of your own spell, which is why you're not getting it. It doesnt need to focus on either, its a Red Way spell due to the explosion (consider this chaos if you must) and the fire resulting from. The spell can be canceled, its not a guaranteed suicide once it happens. Another person can kill you and that would set it off.
This makes it a choice between 'Can I kill him before the spell gains power, with him likely on the defensive', and 'Do we just leave him and run the heck away, and will he be able to deactivate it in time after we do?' which is a chaotic choice in itself.
on the thread for the spell itself (which I suggest you read if you'll be lecturing me on a spell you didn't come up with.) Aramara suggested there be a new glyph itself, Explosion, which would be needed for the spell.
I'd prefer it if you put down what I thought up, and if you had another idea put it down as your own spell. Its not like the Dev's have to even consider it if my way sucks, won't bother me since it was just a fun idea I put up. Heck, maybe they'll see your version and mine and prefer yours. The spell is Red Way in my mind, since the most important bit is the explosion, death just happens to be what triggers it due to this prevent abuse of the spell. (AKA someone with high health sitting it out then blowing it up and surviving while the enemy dies or is wounded enough to finish off). I wasnt completely thinking in terms of settings and how the Way's work, i was also thinking of practical implication in the game and abuse of it.