The ability will trigger again at the beginning of the cards owners next upkeep.
paying a price for being able to use the creatures power
In Pioneer, with decks that are both resilient to interaction and can quickly go over the top like Lotus, Mono-Green, Convoke I see two key scarce resources: High impact one mana cards- Your list on which make the cut for high-impact will differ, but I think it is safe to say there are fewer than 10 in the entire format: Llanowar Elves, Elvish Mystic, Fatal Push, Thoughtseize, Consider and a few others
Speaking of just big and demony, Desecration Demon is quite a lot of card for the mana and not the kind of drawback that will wreak you, just one that leads to a bit of a dead do nothing card too much of the time for this to be all that good
Immersive cards have a unique grey swirling border to help make them more easily distinguishable, and when tapped on, they will begin an animation that gives a tour of the world beyond the illustration on the front
And if X is greater than (or equal to) the number of cards in your library, you win the game