Obsidian Charmaw — ruling 1

Obsidian Charmaw's first ability counts each land your opponents control that would produce {C} if one of that land's abilities resolved. It doesn't matter whether that land's controller could currently activate the ability or not.

Obsidian Charmaw : règles, fonctionnement et interactions (MTG)

Obsidian Charmaw 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

This spell costs less to cast for each land your opponents control that could produce . Flying When this creature enters, destroy target nonbasic land an opponent controls.

How it works : Obsidian Charmaw

Original English text — Wizards of the Coast / Scryfall

#1June 18, 2021· Wizards of the Coast
Obsidian Charmaw's first ability counts each land your opponents control that would produce if one of that land's abilities resolved. It doesn't matter whether that land's controller could currently activate the ability or not.
No other card is named in this ruling.