I forgot about it´s weakness, so you have a point. But I would have to disagree about electric- that has got to be one of the worst types right now! I don´t think Tapu Koko will see much play, and Jolteon is mainly a one of in Lock/Toolbox kind of decks. But hey, it´s way better than steel, which only has stuff like Solgaleo and Mega Scizor, and Psychic except for Mega Mewtwo.
Tapu Koko is a card I've had to talk about twice now... once during my set analysis, and once during the Acerola analysis.
Tapu Koko's GX attack will OHKO Darkrai, Yveltal, Mega Mewtwo... anything that stacks energy.
His 130 damage attack will OHKO M Ray and Yveltal, due to weakness.
It 2HKOs everything else...
and the Tapus have no weakness.
When Acerola comes out, you can basically Max Potion it, as the ability allows you to instantly reset it.
The only flaw the card has, is it
technically uses 3 attachments, though we can use Electrode to attack turn 1 (if you want to run Wally).
P.S. Mega Gardevoir is also Psychic~