Jack Noir first used them to destroy the Dersite and Prospitian armies and part of the Battlefield in the Beta kids’ session. He then used them to destroy Prospit.

Jadesprite is Jade’s dreamself and she was prototyped with Bec so when Jade died on her Quest Bed, Jadesprite went godtier and she retained some dog features including his ears. 

For trolls, they conceal their wings and change out of the outfit. Humans can just change their clothes. 

Brain ghost Dirk is a projection in Jake’s mind that only he can see. He’s a startlingly close approximation of Dirk’s mannerisms and behavior based on Jake’s intimate knowledge of him. Jake can actually bring him into existence once he tapped his full Page powers.

The Alpha kids’ Jack Noir looked into Lil Cal’s eyes and was possessed by Caliborn. He then stabbed out his eyes and replaced them with Lil Cal’s and cut off one leg and replaced it with a golden spike.

Yes, Dersites and Prospitians can experience the full range of quadrants. 

No, we’ve never seen what happens after players enter the new universe.

They go through the door that appears underneath Skaia once Bilious Slick is done growing and enter the new universe. 

Karkat is her patron troll. He helped her extensively throughout Act 5 Act 2 and helped her coordinate her plan to escape her session in [S] Cascade. 

The Condesce sent them away from Alternia to prevent another rebellion like the one caused by the Summoner.