Name: Twilight Sparkle
Species: Cosmic Princess Ponymon
Type: Psychic/Cosmic
Ability: Forewarn
Gmax Move: Gmax Twilock — Prevents all female targets from switching out.

PonyDex Entry:
Spike acts as Twilight's guardian, fiercely defending her from attacks and even attacking for her on her behalf at times.

Origins: A princess trapped in a tower, guarded by a ferocious dragon, Rapunzel, galaxies.

NOTE:
Even though Spike still retains his own Gigantamax form, I thought it'd be fun to incorporate him in Twilight's design, since he is often around her.