The Celebrations set features reprints of classic cards - so for me, the holy grails are the reprints of Charizard, Blastoise, and Venusaur, looking exactly as they did back in their nineties Base Set configuration, just with an extra 25th anniversary slapped on top
If you're thinking of playing Historic Brawl, make sure you don't have these cards in your deck: Runed Halo Gideon's Intervention Meddling Mage Pithing Needle MTG Explorer banlist Explorer is another digital format for MTG Arena, which this time around features legal cards from the Pioneer format

Beast Whisperer Whenever you cast a creature spell, draw a card Elder Gargaroth Vigilance, reach, trample Whenever Elder Gargaroth attacks or blocks, choose one Create a 3/3 green Beast creature token You gain 3 life Draw a card Ohran Frostfang Attacking creatures you control have deathtouch Whenever a creature you control deals combat damage to a player, draw a card Regal Force When Regal Force enters the battlefield, draw a card for each green creature you control Runic Armasaur Whenever an opponent activates an ability of a creature or land that isnt a mana ability, you may draw a card Toski, Bearer of Secrets This spell cant be countered Indestructible Toski, Bearer of Secrets attacks each combat if able Whenever a creature you control deals combat damage to a player, draw a card Non-Budget Enchantment Decks If you are playing an enchantment-focused deck, these are nearly mandatory inclusions to ensure you green card draw strategy

Altergeist, while normally much weaker than the other decks, has a chance to shine here