mtg cards cannot be exiled Still new to the game, does this mean I can cast spells of my opponents that are or any I have in my hand? Any cards that can play

The value of X is calculated only once, as Eldrazi Linebreaker's last ability resolves

After all, uh, you've got to be fairly heroic to willingly run up 59 flights of stairs to save your friend

This primarily applies to Izzet Phoenix, and recently Azorius Control due to the addition of Narset, explaining things like the industry-standard one Magmatic Sinkhole in the former and one Timely Reinforcements in the latter

Then the Blue artifact will tap for double X, and everyone will draw X

However, we posit that these decks are also great for experienced players who may have trouble upgrading complex precons , or building their own decks from scratch