Firestorm (Pyrocumulonimbus)

Req: Fire&Lightning spells cast from adjacent squares
Casters roll arcana or spellcasting ability check.
Choose a # of effects based on the total.
-< 30: 1 effect; 31-40: 2 effects; 40-45 3 effects;
46+ all effects.
•+1 to Spell save DC, +1d6 to each spell's damage
•Choose AOE/range of either spell for both effects
•Make one save against the higher spell save DC
{bull}The next healing or damaging spell you do
before the end of your next turn increases by 1d6