Fluctuator allows for free cycling, which may not seem like a big deal now, but in a Standard full of cyclers, it was pretty nuts in Astral Rift
Grixis decks also have a solid number of cards that can ping players for damage , like Underworld Dreams or Stormfist Crusader
Trainer Cards are split into two types primarily: Items, which you can use as many of as youd like each round, and Supporters, which you can only use once per round
This is easy enough to do with cards like Walking Ballista, Stonecoil Serpent, and Hangarback Walker
Unlike in the physical format or Magic the Gathering Online, Arena does not offer card trading between players nor individual card purchase platform
One of those cards is a Blastoise EX promo card from the Pokemon XY set that released in 2013