Alright. So reusing the "brief" summaries I made for other things with them;
Tai is a chimera made by Eggman. Tai is a hybrid between an echidna and a tenric. Her skin is pinkish, and she can have a bit of a temper. And by a bit, I mean a lot. She's also silent and stoic, and (once freed from imprisonment by Radic, Nex and Gamma) is determined to destroy Doctor Eggman. Her powers allow her to manipulate kinetic energy into pulses and bursts of energy. They grow more powerful with her rage. However, she is loyal. No one (not even herself or Eggman) know who she used to be before the experiments. She now travels with Radic, Nex and Gamma. Radic and Gamma are her closest friends, as they can best sympathize with her.
Nex is a lynx with incredible skills with technology. He's a master mechanic and a skilled battler. He originally came from Soumerica (yes, that's a canon name) but left for Northamer (again, actually canon) on a journey. He met Radic and the two became friends. They've been allies ever since. He wears two blades on the backs of his hands, held in place by strong bracelets. The blades can be used to climb walls, jack into tech ports and bash enemies. He's pretty strong, but he's a glass canon. He built Radic's favorite ship, the Comet, and rebuilt E-102 Gamma's AI from fragments left on the first Egg Carrier. He's pretty cool.