Firestorm

is a Tier 7 Fire + Air Path Spell.

The caster conjures a massive firestorm over a large volume of space, easily covering the size of a town and hundreds of meters high at base tier. The firestorm is a massive vortex of extreme heat that is densely packed with embers and which can cause spontaneous combustion of anything combustible within its volume of effect. Anyone caught unprotected within the firestorm will likely be burned to death within minutes. The required investment into this spell is substantial; the firestorm gradually manifests over the first 5 minutes of maintaining the spell, and only dissipates over 5 minutes after the caster stops maintaining the spell.