Curious: Will Ekko's "time rewind" ability be global and map wide, or will it be AoE?

Depending on whether Ekko's inevitable signature "time rewind" ability affects the entire map, or just an area around him, this ability could serve several unique functions. I'm personally hoping it's just a large AoE around him, and anybody inside gets "rewound".

Because A) Sitting in top lane when Ekko uses ult in bot lane and getting thrown back 4 seconds would be REALLY annoying, especially if he's an ally.

B) A global reverse would be immensely powerful, and that would definitely shrink the rest of his kit

C) It could be used to make some very unique and interesting plays. EX: Ahri ults to flee from Ekko, Ekko ults her and she gets rewound. Meanwhile, from outside the rewind range allied ranged champ uses the rewind time to kill the "pulled in" Ahri.

D) Abilities that can likely negatively affect allies should be kept to a minimum. Look at Anivia troll wall and Bard ult for prime examples. Even Kalista ult is trolly.