Feline Sovereign — ruling 1

Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a Cat you control may become lethal if Feline Sovereign leaves the battlefield during that turn.

Feline Sovereign : règles, fonctionnement et interactions (MTG)

Feline Sovereign is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Other Cats you control get +1/+1 and have protection from Dogs. Whenever one or more Cats you control deal combat damage to a player, destroy up to one target artifact or enchantment that player controls.

How it works : Feline Sovereign

Original English text — Wizards of the Coast / Scryfall

#1June 23, 2020· Wizards of the Coast
Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a Cat you control may become lethal if Feline Sovereign leaves the battlefield during that turn.
No other card is named in this ruling.