Arena Athlete

Creature — Human

Produces: nothing.

Cares about: a creature being cast.

Partners

117 cards can cause a creature being cast.

1. Radiant Performer — When Radiant Performer is cast, Arena Athlete triggers
2. Elemental Time Flamingo — When a creature is cast thanks to Elemental Time Flamingo, Arena Athlete triggers
3. Dreadhorde Arcanist — When Dreadhorde Arcanist is cast, Arena Athlete triggers
4. Transforming Flourish — When Transforming Flourish is cast, Arena Athlete triggers
5. Strago and Relm — When Strago and Relm is cast, Arena Athlete triggers
6. Izzet Chemister — When Izzet Chemister is cast, Arena Athlete triggers
7. Nico Minoru, Runaway — When Nico Minoru, Runaway is cast, Arena Athlete triggers
8. Territorial Bruntar — When Territorial Bruntar is cast, Arena Athlete triggers

17 other cards cause it too, equally specific. The ones shown are the best connected.