Nexus Clash

In the spirit of keeping fallen's (newfound?) identity as a WIN MORE class, and in order to make it not be subject to spawning 20 HP, 45% to hit 5 damage balls of disappointment, I propose this to be added to the Fallen's desecrate table

Traitor's Exultation
On getting a kill, gain 15 mana.
Gets the Traitor's Exultation status effect for... 10 ticks? Multiple procs refresh the duration instead of stacking it.
While under the effects of Traitor's Exultation, every 10 points of mana you're above the mana cap gives you +1 damage
Can't go over the same mana cap you get from consuming soul ice
While under the effect of Traitor's Exultation, you can activate it to consume ALL MANA and get 1 AP for every 15 mana spent

"but ex-paladins don't have desecrate so wh-" yeah ex-shepherds do though. pact up, fella, what's wrong with you

Obscene amounts of MP regain fits well with Fallen's current skills revolving around MP consumption.

Ex-Shepherds will get more mana from double spells, but most of them will be spellcasting for optimal damage, so will burn through more mana anyway.

+1 damage for each 10 MP above cap might be a bit much - Fallen has enough incentive for gaining more MP (MP respawns, MP feeding into covetous spite for direct damage, Imperious Demeanor when above 2/3rds MP).

1 AP for every 15 MP spent seems like a decent pay-off mechanic while being significantly less broken than the old Fallen AP payouts:

Old Fallen = Expected value of 4.9 AP per kill (not counting the +1/2 AP guaranteed payout from kills).
Traitor's Exultation Fallen = Expected value of an extra 0.7 AP per kill.

I'm trying to think of potential abuse cases where you could overcap MP in order to get more AP. Soul Ice/MR stacking would let you get to ~110 MP preraid, which would amount to about 7 or 8 AP. Avaricious Oblation stacking does exist - but with infernal jets in their current state, it's hard to think of a way in which you could reasonably stack more than 100 MP pre-raid with it. In any case, unless there's a way for Fallens to stack > 200 AP, it's hard to see this competing with AP stacking via amphetamines, which is offset by its logistical costs, which means it's probably safe to put in the game.

Nice consolation prize for the Fallen, not nearly as busted as 50 AP from 8 kills.

Personally, the overall "get a MP regen proc" and the "gain damage for high MP" parts are really interesting, although I'm not convinced with the details.