If youve played for a while, or have invested in getting the older cards in Arena, you might look into building a competitive deck in Historic, Explorer, or Pioneer
This makes sacrifice loops with cards like Viscera Seer or Phyrexian Altar extremely potent
As someone who often uses creatures for removal, card draw, and ramp, Humility is especially well-positioned to ruin most of the game plans for my personal decks
The tricky part comes in narrowing your card pool down to what you can afford versus the purpose of each card inside the deck
Ugin, the Spirit Dragon It seems fairly nutty to have Ugin only at sixth on this list as he seems to be the complete package
Single Strike Urshifu V #151 Ultra Rare Just as the artwork for Rapid Strike Urshifu V matches a quick and agile fighting style, the artwork for Single Strike Urshifu shows clear indication of a single strike