As a 30th level War Mage you are able to weave together two spells to create a burst of spell power. Because of your dedication to your chosen craft and your intimate relationship with the arcane you unlock a primordial side of magic.  You may combine two leveled spells adding together their levels and damage rolls to fire off one extravagant spell. To do so you sacrifice 2 spell slots and can not fire off any more leveled spells until the end of your next turn. You may only use this power equal to half your proficiency bonus rounded down per long rest. The spells used must be the same spell.