Abomination of Llanowar counts both the Elves on your battlefield and the Elf cards in your graveyard to determine its power and toughness
I know I've only scratched the surface of thematic decks
You can pay two and tap it to keep all other artifacts tapped down while it remains tapped - essentially keeping all artifact creatures and mana rocks out of the game, if you're willing to pay that cost each turn
It is summoned through Zera Ritual (Ritual Spell), where players must tribute Monsters of Levels that equal Zera the Mants 8-Star classification
Obviously getting a card in or out a sleeve 100x times will scratch it, I limited the testing from 3 to 5 times inserting a removing a card
Creature - Rogue Halfling Linvala, Shield of Sea Gate Flying At the beginning of combat on your turn, if you have a full party, choose target nonland permanent an opponent controls