Mid-September's direct will reveal this fellow in a trailer against Pikachu.

Jibanyan comes to world!
Decidueye aims the opponent!

Ultra Space is a new stage. The stage changes to UBs worlds and they will appear as Stage Hazards.

Ultra Necrozma and Mega Rayquaza are bosses in Ultimate Emissary

Sceptile is Decidueye's echo fighter.
Zoroark is Lucario's echo fighter but shows similarities with Greninja.

Pichu's role in Ultimate Emissary is save Pikachu from Wolf's spaceship.