Log in using your MTG Arena details, and on the right-hand side of your account dashboard, you'll find a nice, big 'Redeem a code' box
Ive separated them into three categories: touching your cards/game supplies, verbal/non-verbal communication, reputation, and bluffs
they effectively only cost 1 mana since they recoup half the cost instantly
I get that the previous sentence is like nails on the chalkboard for Universes Beyond haters, but I like to imagine what Pippin would do with one of these, and it tracks
Your "Simorgh, Bird of Divinity" will become Level 6, so Tribute Summon it, then Special Summon "Simorgh of Darkness" using its effect
Rampardos is an OP card, but it is kept in check with its Stage 2 evolution requirement and the task of finding Skull Fossil (not obtainable via Pok Ball)