Sic Semper Tyrannosaurus
From Archon Arcana
Sic Semper Tyrannosaurus • Saurian • Action • Uncommon • Play: Move each
from the most powerful creature to your pool and destroy that creature. • Artist: Nicholas Gregory • Card Number: WC (209)

Commentary
If there are multiple creatures that qualify as the most powerful, each is considered “most powerful”. If an ability requires the selection of a single most powerful creature, and multiple creatures are tied, the Active player chooses among the tied creatures.
Source: Most Powerful