Lightning Blast

(You can only have one Master Instant in your
library or sideboard.)
Remove X experience counters from yourself:
•Lightning Blast deals X damage to any target.
If X is 10 or more, you get an emblem with
"Damage you control can't be prevented." and "Creatures your opponents control lose indestructible and can't have indestructible." and
Lightning Blast deals twice X damage divided as
you choose among any number of targets instead.
Exile Lightning Blast.