Explosive Soul

Megumin has blessed your soul with the ultimate magic of Explosion! You exhaust yourself in your endeavor to create larger and larger explosions, other magic is useless and rarely will you learn any spells that don't go "Boom". Picking this class you may not multiclass into any other class. 

The Way of Explosions

With your love of explosions, at any given time two thirds of your known spells must be Evocation spells. Evocation spells all have their damage converted to be half fire and half force damage when you cast them. 

Explosion!

Starting at 1st level you learn the Explosion! spell. Your love for Explosion magic has taught you how to amplify this spell using your sorcery points. As part of the special action in casting it, you may spend sorcery points to increase the damage and size. This can be used with other Metamagic's except for Subtle spell. Referencing the "Creating Spell Slots" chart you can add those spells slots created with Sorcery points to increase the damage further on top of casting the spell at a higher level, see example below. For every 3 levels added to the power of this spell with Sorcery points, you get 1 level of Exhaustion rounded up. This spell does not count towards your known spell list. 

Example: Casting Explosion at 6th level is 5d8 fire + 5d8 force damage. If you were to spend 12 sorcery points creating two 4th level spells slots while casting this, you add those to the level at which it is cast effectively casting the spell at 14th level for 14d8 fire + 14d8 force damage

Explosive Heart

At 6th level, you gain resistance to fire and force damage. In addition, spells you cast ignore resistance to fire and force damage. 

Erupting Explosions

Starting at 14th level, you gain the ability to fly as a bonus action by creating small explosions at your hands and feet blasting you through the air. You have a fly speed of 40 feet for the round and at the start of your next turn start to fall unless you spend your bonus action again to continue. 

In addition, your practice with Explosive magic has given you the ability to recover better from its effects. Greater Restoration heals 2 points of exhaustion for you and you can now recover 1 point of exhaustion after two consecutive short rests or 2 points of exhaustion after one long rest. 

You are the Bomb

At 18th level, you gain immunity to fire and force damage. In addition, any spell or effect you create ignores resistance to fire or force damage and treats immunity to fire or force damage as resistance to fire or force damage instead. 

You also learn how to channel explosion magic through yourself. You are able to cast explosion on yourself and spend hit die to buff the damage. For every 1 hit die spent, you add 1d8 fire and 1d8 force damage to the spell. The spell changes to a sphere centered on you and increases the radius by 5 feet for every hit die spent as well as the forced movement by 5 feet for every hit die spent.