[Expanded] Jolteon-GX

They just Guzma and use a GX pokemon to attack, 100% Invincible is a massive overstatement here

This is a really fun idea, though it's a little flawed. Like Deseus said you're very prone to being bossed, I think having VS Seeker to recycle Iono and maybe adding Marnie over Peony would be useful for hand control reasons (and obviously recycling Misty/Lorelei is majorly beneficial). I don't think you need Mimikyu at all - maybe you could catch your opponent on an Escape Rope but the only decks that really run that have single prize outs like Cramorant, when your opponent bosses you they choose the Pokemon you switch into so they just wouldn't choose Mimikyu if they can't hit it. Similarly the water energy seems useless, are you really going to be able to build up three energy on Vaporeon without it getting bossed just to do 70 damage? Exeggcute (Plasma Freeze) would also be really helpful, since you can basically pay Misty/Lorelei's discarding effect for almost free every turn, and you can use it for Ultra Ball and Electromagnetic Radar too (you can use their ability as many times as you like per turn because of a weird ruling, ignore the actual text on the ability lmao).

A couple of other quickfire ideas - Dedenne-GX is searchable off of Radar and can help you get set up, Thunder Mountain ◇ lets you use Jolteon's attack for a single energy, I personally prefer Mew (Unbroken Bonds) over Manaphy in offensive decks since that attack can sometimes come in handy to chase KOs, and though I understand if you don't want to use it because of the high price tag Dowsing Machine is good in any Expanded deck.

Also, Flareon (Cosmic Eclipse) provides the same effect as Regieleki though it can't be stacked. Probably not as good but it feels mean to not invite the fire boy to the gen 1 family reunion lol

I agree with P.P.A.D that this deck is flawed. Adding the 4 Exeggcute is essential in a deck that focuses on discarding. Thunder Mountain wouldn't work because it only works on electric types. Electropower is another card worth considering, along with Computer Search, speed energy, Bodybuilding Dumbbells, more copies of battle vip, N, energy recycler, Miryum(I think that's how you spell her name😅), VS Seeker, Choice Band, and maybe Miriaidon.

Thanks JaceWindu18, Paisley Park, After Dark, and Deseus | Legacy of Wrath for the feedback, I'll try to make these changes immediately.