You've waited weeks or months
If a creature with +1/+1 counters on it receives an equal number of -1/-1 counters and this causes it to be destroyed by lethal damage or put into its owner's graveyard for having 0 or less toughness, Nikara's last ability triggers
(It cant be blocked as long as defending player controls a Mountain.) Illustrated by Mark Poole Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Legal Comp
As for spells to flash in, you can do so much with a surprise Narset, Parter of Veils in response to a Brainstorm, an unexpected Elesh Norn, Grand Cenobite when an opponent swings out at you, or a sudden The One Ring when somebody tries to take you out
If youre missing any of the cards for any of the above decks, be sure to pick up some PTCGL codes while you are here
Electrike (Mega Shine) is not available in Regular Packs