You can actually see a crying Pinkie in the center balloon, that a really nice touch.  
Theory Time  
Her Wish- Being able to throw a giant humungous humongous party for everypony

Creepy design (awesome, though). This is my theory on what would happen to Magical Filly Pinkie Pie (wish isn’t included):
 
At first, defeating Witches with her friends would seem like fun to Pinkie. She was getting rid of creatures that spread around misery and despair, in turn spreading joy all around. Heck, she may even have thrown parties to celebrate the defeat of Witches. Perhaps her least favorite aspect of the job would be having to fight rivals for Grief Seeds or territory, thinking of it as ‘mean’ and ‘sad’. Like Rarity (in my opinion) she would probably try to think of a way to share them out, rarely ever actually fighting it out unless she was REALLY provoked.  
Finding out what the Witches really were would…take its toll. Finding out that she was a victim of despair, the thing she had been trying so hard to repel, would destroy Pinkie Pie. The realization that sadness was a thing that could not be repented would be a harsh wake-up call, probably leading to her demise. I can see her doing what Mami did during that one timeline: trying to kill all her friends first, legitimately believing she was saving them from a fate worse than death. Eventually Pinkie would succumb to the unhappiness, becoming this wonderfully disturbing Witch.
 
This is just my idea, though! :-)

“Pinkamena”

I’m reminded of my design for laughter elementals.

The (musical) runes read as “PINKAMENA”.