If Portable Hole leaves the battlefield before its ability resolves, the target permanent won't be exiled
However, once burn multipliers hit the battlefield, this is when you can start turning the game around
As of 2024, there have been over 100 MTG sets released and more are always being made, so there is a degree of certainty that your favorite character or IP will eventually find its way into the gathering, especially with the growth of Universes Beyond crossover sets in recent years, including the mighty MTG Lord of the Rings set
4 and lasting until the 12th, that will no longer be true (and technically it hasn't been true since WotC decided to do functionally unique box topper cards such as with Firesong and Sunspeaker in Dominaria and Nexus of Fate in M19 depending on how you look at it)
You may choose both modes if any opponent has eight or more cards in their graveyard, not necessarily all of them