first edition articuno pokemon card Holo Fossil 1st #2 PSA 9 Water Cold Cyclone (70) Move 2 Water Energy from this Pokémon to 1 of your Benched Pokémon Articuno - Legendary Bird Pokémon

So long as you have two extra mana, you can pay four to return it to play with the Deathmantle attached to it while also creating four 1/1 Myr artifact creature tokens

While there isnt going to be a perfect answer for every deck or metagame, Ive found that playing 4-6 is usually a good starting point

Some of the most expensive Trainer cards are Lillie from Ultra Prism (big card draw), Skyla from Boundaries Crossed (who searches any other Trainer card), and Mistys Favor from Unified Minds (searches up to 3 other Supporters)

Not to mention theres no restriction for his mana

Sounds Fair

If not, however, then the flexibility of Fiery ConfluenceFiery Confluence will come in handy, in all likelihood being one of the only artifact removal options in the deck, not to mention an additional utility creature board wipe if needed