Midnight Arsonist — ruling 1

Midnight Arsonist's triggered ability can't target artifacts that have either activated or triggered mana abilities. An activated mana ability is one that could add mana as it resolves, doesn't have a target, and isn't a loyalty ability. A triggered mana ability is one that could add mana as it resolves and triggers based on an activated mana ability.

Midnight Arsonist : règles, fonctionnement et interactions (MTG)

Midnight Arsonist 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

When this creature enters, destroy up to X target artifacts without mana abilities, where X is the number of Vampires you control.

How it works : Midnight Arsonist

Original English text — Wizards of the Coast / Scryfall

#1November 19, 2021· Wizards of the Coast
Midnight Arsonist's triggered ability can't target artifacts that have either activated or triggered mana abilities. An activated mana ability is one that could add mana as it resolves, doesn't have a target, and isn't a loyalty ability. A triggered mana ability is one that could add mana as it resolves and triggers based on an activated mana ability.
No other card is named in this ruling.