stained glass card sleeves Magic: The Gathering MTGS-239 Players Sleeve, Dominaria, Version, Swamp Toys fits all major TCGs 100-Pack Trading Card Sleeves –

destroy it, then, if it was a LIGHT monster, both players send as many cards as possible from their Extra Deck to the GY, but not more than the original Level/Rank of that destroyed monster

You can use [BT19-019 Shellmon]'s When Digivolving effect to play [BT19-082 Yao Qinglan] without paying the cost

2021-03-19 Flashback [cost] means You may cast this card from your graveyard by paying [cost] rather than paying its mana cost and If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack. 2021-03-19 You must still follow any timing restrictions and permissions, including those based on the card's type

He's a self-fueling engine

Legality depends on the tournament format -- Cloud, Midgar Mercenary can be legal in some formats and banned or restricted in others