Yusei realizes her threat was a bluff, so he stops his Duel Runner too
Hoopa ex's first attack, "Energy Crush", deals 50 damage for each energy attached to all the opponent's Pokmon , which is great against decks like Hydrapple ex and Toedscruel that need to have a plethora of energy attached to the board to deal damage
Everything in the lair is themed around tomb raiding, and lots of it is valuable: Search for Azcanta, Anger of the Gods, Bow of Nylea, Shadowspear, Academy Ruins Through the Wormhole - The cards in this Secret Lair aren't particularly valuable, but the contents - Lightning Greaves, Arcane Signet, Sol Ring, Thought Vessel, and Command Tower - are a complete playset of Commander essentials, in a beautiful and consistent art style by Dani Pendergast
Lightning can use Stagger on enemy players, which is especially terrifying since the card has Trample and Lifelink