Surveil is a cool and somewhat rare mechanic that we dont see often on a Modern playable card, and probably for a good reason
Sorin, Imperious Bloodlord is a black planeswalker with three abilities that are payoffs for playing vampires, but the last one can be especially brutal and almost makes it count as a turn 3 Bloodthirsty Conqueror
Now, this isnt all that helpful if youre going to be flickering it again, because itll fall off, but its a nice bonus when you just need to protect a Creature or feel like using something akin to a combat trick
However, you aren't exactly under any pressure at all
This makes them the first spells other than legendary Creatures that can be in the command zone
A Halo foil rare or mythic rare will appear in 10% of Collector Boosters