2021-02-05 : As the boast ability resolves, first the next opponent in turn order chooses a creature or planeswalker they control. Then each other opponent in turn order chooses a creature or planeswalker they control, knowing the choices made before their choice. Then all chosen creatures and planeswalkers are sacrificed at the same time.

2021-02-05 : Eradicator Valkyrie can’t be the target of abilities whose source is a planeswalker an opponent controls.