Discard "Burning Abyss" monsters to activate this card's effect, as their effects usually replace themselves, and as such, can be used as Tributes for the Tribute Summons for "U.A." monsters.
Use "Feast of the Wild LV5" to Special Summon this card (along with another appropriate monster) from your hand or Graveyard, which you can possibly use for a Rank 5 Xyz Summon, as a Tribute for a Tribute Summon (to trigger the effect of "U.A. Stadium"), or as a way to facilitate the Special Summons of the other "U.A." monsters in your hand.