2 cards where the text includes “charge” and the text includes “counter” and the card types include “artifact” and it’s legal in Standard

Dragonspark Reactor (Kamigawa: Neon Dynasty #137)

Dragonspark Reactor {1}{R}

Artifact

Whenever Dragonspark Reactor or another artifact enters the battlefield under your control, put a charge counter on Dragonspark Reactor.

{4}, Sacrifice Dragonspark Reactor: It deals damage equal to the number of charge counters on it to target player and that much damage to up to one target creature.

Illustrated by Billy Christian

Standard
Alchemy
Pioneer
Explorer
Modern
Historic
Legacy
Brawl
Vintage
Timeless
Commander
Pauper
Oathbreaker
Penny
Geistflame Reservoir (Innistrad: Midnight Hunt #142)

Geistflame Reservoir {2}{R}

Artifact

Whenever you cast an instant or sorcery spell, put a charge counter on Geistflame Reservoir.

{1}{R}, {T}, Remove any number of charge counters from Geistflame Reservoir: It deals that much damage to any target.

{1}{R}, {T}: Exile the top card of your library. You may play that card this turn.

Illustrated by Anna Christenson

Standard
Alchemy
Pioneer
Explorer
Modern
Historic
Legacy
Brawl
Vintage
Timeless
Commander
Pauper
Oathbreaker
Penny

Though this query has ended, its relics still slumber in New Argive.