MTG Foundations Jumpstart Taeko, the Patient Avalanche (Anime)

Taeko, the Patient Avalanche enters tapped. Whenever another creature you control leaves the battlefield, if it didn't die, scry 1 and put a +1/+1 counter on Taeko. Whenever Taeko attacks, you may pay {U/B}. When you do, target attacking creature can't be blocked this turn.