Megas are Stage 1 and Stage 2 cards, and can directly evolve from their respective Basic and Stage 1 cards (a rule followed in the physical TCG as well)
Online retailers should strengthen anti-scalping measures with better bot detection, stricter purchase limits and verified customer queues
But sometimes you just need a reliable way to burn your opponent from some crazy high damage
Kaiser Colosseum is a Continuous Spell card that, while active, prevents the opponent from controlling more monsters that the controller of this card
If you somehow can't discard a card (probably because you had no cards in hand and another effect prevented you from drawing cards), you won't put any counters on Cait no matter whether or not the defending player discarded a card or what that card's mana value is
If your local store lighting is harsh, matte sleeves can reduce glare and improve the experience.