The value of X is determined only once, as Summon: Yojimbo's fourth chapter ability resolves
With a powerful combination of white, blue, and black cards, you can cast intricate spells, control the game, and manipulate the cards for surprise victories
White has a handful of options, as well as lots of ways to make a ton of small creature tokens that you can use as chump blockers or sacrifice to trigger your morbid effects
How long it will hold onto the record remains to be seen
As for removal, the red-green archetype uses the Fight mechanic, and one-sided "bite" effects, to destroy almost any creature the opponent can put onto the battlefield
In a format where attacking a specific opponent without a reason is too often taken as a personal offense, introducing a simple reward for doing so is usually enough to incentivize players to rightly commit to the combat phase, leading to more interactive play patterns and a quicker game pace