Once that happens, the value of X won't change later in the turn even if the number of cards in your hand changes
There are two places these cards are marked, and that's great, exept that the SIDE marks are just far enough apart to not be taken in at the same time...extending the time to read the marks another nano-second or two
The Doctor Who Blast from the Past Commander Deck includes 1 ready-to-play Green-White-Blue deck of 100 Magic cards (2 Rainbow Foil Legendary Creature cards, 98 nonfoil cards), 10 Planechase cards, 1 six-sided planar die, a 2-card Collector Booster Sample Pack (contains 2 Rainbow Foil or nonfoil special treatment cards, with 1 Common or Uncommon and 1 card of rarity Rare or higher), 1 foil-etched Display Commander (a thick cardstock copy of the commander card with foil etched into the cards border and art), 10 double-sided tokens, 1 deck box (can hold 100 sleeved cards), 1 Life Wheel, 1 strategy insert, and 1 reference card
All jokes aside, this thing is a solid pickup for monowhite, combining Reconnaissance with card draw, token production, and an alternate win condition
No matter which stack your opponent chooses, it's a winning scenario for you