It basically supercharges every synergy in the deck
10 Errant, Street Artist - Cheating And Stealing Errant, Street Artist is an incredibly cheap commander that is all about copying any target spell that you've cheated into play, whether that be through stealing cards from enemies, pulling straight out of your deck, or through copying permanents that were cast
Some Disassembly Required comes with a fairly creepy flavor text, implying that whoever is operating the vat in the art is looking to sacrifice Santa or another jolly holiday character for their keywords
It just changes where you can use them
Its design comes from the Yuki-onna of Japanese folklore, the spirit of a woman lost in the snowy mountains
MTG's Avatar Aang was the first card to be revealed from the set, and it single-handedly raised the price of older cards for potential Commander combos