Yeah. It's slow, but it doesn't matter how many people are killed that way. Just don't have anyone budge for the 40 turns it would take to kill Solstice by poison, or perhaps speed the process a bit by using up excess spells (summons, that sort of thing). As long as it ends up with Arazen manaflared, solstice dead or at least out of dispel, and Arazen with at least one attack spell, there is no way I can see right now that Rad could win.