Way Of The Thermonuclear Bomb

Monks of the Way Of The Thermonuclear Bomb follow a tradition of complete and utter indiscriminate destruction. They seek glory in unrivaled power over fusion reactions, and specialise in abilities that allow them to use this force to annihilate their enemies. Many of these monks serve as powerful masters of combat, able to demolish entire armies with blasts so strong they are as if god himself decided to smite the poor fellow on the receiving end.    

Power Of Fusion:

You may imbue your fists with nuclear power. When you make an unarmed strike against a creature, you can spend 1 ki point to add an extra 2d4 fire damage to your unarmed attack. The opponent must also succeed on a strength saving throw or be pushed back by 10 feet away from you. At 6th level this increases to 2d6, and at 11th level 2d8. It caps at 2d10 at level 17.  

Arms Race:

Starting at 6th level, you are in constant competition to outperform your enemies. When an enemy casts a spell you may expend 3 ki points to use a reaction to mimic an enemy spell, as long as its spell level (Or the level of the spell slot it was cast with) is less than or equal to one third your monk level, rounded up. When you mimic this spell, it is cast with a spell slot level 1 higher than the enemy cast it with. You must finish a long or short rest before you can use this ability again.

Imbue Nuclear Power:

Starting at 11th level, you can enhance weapons with thermonuclear energy. When you make a thrown weapon attack, or use Deflect Missiles to make a ranged attack with a projectile that you have caught, you can expend 2 ki points to add 4d6 radiant damage and 2d6 force damage to the thrown attack. The target must also succeed on a strength saving throw or be pushed back by 30ft. 

The power of the sun

Starting at 17th level, you have become a master of the nuclear warhead. Once per short or long rest, you may expend 4 ki points to summon a nuclear bomb from the mystical energy of ki. This bomb can appear at any point within 300 miles of yourself, it always appears at least 100 feet above the ground. When the bomb makes contact with the ground, or if it takes any damage, it explodes. When it explodes, all enemies within a 6 mile radius take 100d10 radiant damage and 100d10 force damage. They are also blinded, deafened and knocked prone if the power of the sun didn't kill them already. This is your final form, all will fear you now.