A key point here is that were not discussing every single structure deck in Yu-Gi-Oh Master Duel, but are discussing the upper echelon of Master Duel structure decks
Play cute, not competitive Pot of Greed
Metalfoes Fusion Monsters generally require one Metalfoes Monster, along with one or more Monsters that belong to a more generic category like Monsters with less than 3,000 attack points for Metalfoes Crimsonite
Extra Deck 15 Millennium-Eyes Restrict X DARK Level 1 [ Spellcaster / FusionEffect ] ATK 0 DEF 0 "Relinquished" + 1 Effect Monster Once per turn, when your opponent activates a monster effect (Quick Effect): You can target 1 Effect Monster in your opponent's field or GY
In addition to being a powerhouse on the battlefield, this Dragon, like other Toon monsters, can attack the opponent directly, albeit at the cost of 500 of their owner's Life Points