If there is one deck I hate playing against right now, it has to be Lugia Vstar. With Lugia Vstar as the main attacker, Archaeops giving support through it's primal turbo ability and then Radiant Charizard being there to finish you off, it's a right royal pain to beat.
Let's start off talking about the main card of the deck, Lugia Vstar. With 280HP and a Tempest Dive attack for four colourless energy that does 220 dmage plus removes a stadium from display, it hits hard and you need to hit it harder to beat it. The Vstar power is the real issue here though, with it allowing you to take two colourless pokemon from your discard pile and add them to your bench (as long as they don't have rule boxes).
This then allows for two Archaeops (that can be discarded through the likes of Ultra Ball and Proffesor's Research) to come onto the bench and use primal turbo to attach energy to Lugia. It's simple in design but deadly in it's effectiveness.
You then have Radiant Charizard, the heaviest hitter of the deck with it's Combustion Blast attack hitting for 250 for four colourless energies and a fire energy. That is enough to one hit KO most Pokemon V's, and with a choice belt attached, enough to take out the majority of Pokemon Vstar too.
So what else makes this deck so hard to beat. Well, to start, there's not really any counter. While Path to the Peak will prevent Lugia Vstar using it's Vstar ability, there is nothing to stop your opponent to remove it by playing their own stadium, or by just slowly powering up Lugia V or Vstar and then attacking with Tempest Dive to remove the stadium.
Lugia is vulnerable to electric type pokemon, but until the releas of Miraidon ex in Scarlett and Violet later this year, the only real option in electric type Pokemon is Vikavolt V but that can be one hit KO'd for two prizes and requires two electric energies and a colourless energy to use Zap Cannon for 190 damage (before weakness), but this attack makes you discard two energies.
Right now, Lugia V can be purchased in stor for £7, while Radiant Charizard is available for £20. Lugia Vstar is available for £11 and Archaeops can be found in Silver Tempest booster packs.