Jeskai Runemark — ruling 1

Whether a creature has flying is checked as blocking creatures are declared. Once the enchanted creature blocks or is blocked, losing flying won’t change or undo that block.

Jeskai Runemark : règles, fonctionnement et interactions (MTG)

Jeskai Runemark 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

Enchant creature Enchanted creature gets +2/+2. Enchanted creature has flying as long as you control a red or white permanent.

How it works : Jeskai Runemark

Original English text — Wizards of the Coast / Scryfall

#1November 24, 2014· Wizards of the Coast
Whether a creature has flying is checked as blocking creatures are declared. Once the enchanted creature blocks or is blocked, losing flying won’t change or undo that block.
No other card is named in this ruling.