If your opponent mills your entire deck, you usually have until your next draw step to solve that problem somehow, whether that means winning the game yourself or finding a way to put cards back into your library
(2010-06-15) If a spell has restrictions on when it can be cast (for example, Cast [this spell] only during the declare blockers step), those restrictions may prevent you from casting it from exile during your upkeep
If an effect cares about the rules text, flavor text, or watermarks of a creature who's had its text box stolen, the effect sees nothing but an empty pit of sadness
There are many effects that can Special Summon monsters, and Tuner cards like Plaguespreader Zombie make Synchro Summons a snap
The reverse holo in PSA 9 or 10 is the version that carries real upside, driven by crossover interest from Magic collectors who want a Rush piece and by the scarcity of clean galaxy foil