yugioh theme decks Yu-Gi-Oh! Trading Cards Legendary II, Gold : Toys & Games another copy of 1 of 6 cards from that Deck Yu-Gi-Oh: ARC-V Saber Force/Dark Legion

[R][C] Fire Mane: 60 damage

While not every deck runs it, many top tier ones do, leaving quite a big hole especially for decks that rely on having energies in the hand to accelerate multiple in a turn, like the powerful Mega Charizard X ex

SR Super Rare Shaddoll Fusion X SPELL Fusion Summon 1 "Shaddoll" Fusion Monster from your Extra Deck, using monsters from your hand or field

Charizard ex has a devastating Move called Crimson Storm which deals 200 damage at the cost of discarding two Fire Energy

Creatures are the primary way you reduce your opponents life total to zero, as they can stay on the battlefield and deal damage for multiple turns