So my thought is explosives... lots of explosives.
"We've Got Explosives!" - Replaces/Upgrades Throw, Shuriken Toss, Glaive Toss, and Deadly Throw with Dynamite/Bombs. Which now cause small explosions of fire damage, to enemies within 3 yards upon impact. (This could include Fan of Knives and Heroic Throw in WotLK)
"Ahh, it's Beautiful!" - Killing an enemy with "We've Got Explosives!" and it's effects, grants a stack of "Ahh, It's beautiful!" Increasing their damage by 0.5%(15% max,) and the damage of your next "KABLOOEY!" by 5%(150% max.) Stacks to 30.
"KABLOOEY!" - Replaces Divine Intervention; You sacrifice yourself to BLOW THEM UP! Dealing 50% of your max health(125% of health from max "Ahh, it's Beautiful!" stacks) as fire damage to enemies within 12 yards. If used while under the effects of 30 "Ah, it's Beautiful!" stacks, negate the self-sacrifice.
Much of it could be subject to change. Names are 'inspired' by the Goblin Sappers of Warcraft 2. Hope you like the concept.