Bone Shredder

Jun 18, 2021 · Paying for echo is always optional. When the echo triggered ability resolves, if you can't pay the echo cost or choose not to, you sacrifice that permanent.

Jun 18, 2021 · Your permanent's echo ability will trigger at the beginning of your upkeep if it entered the battlefield since the beginning of your last upkeep, or if you gained control of it since the beginning of your last upkeep.