Special Summon 1 Ultimate Flagship Ursatron from your Extra Deck by banishing 1 Ursarctic Big Dipper and 1 Drytron Fafnir from your hand and or field, although you can banish 1 of them from your Deck instead if Ursarctic Polari or Drytron Alpha Thuban is on the field. If you would Tribute a monster(s) to activate an Ursarctic or Drytron monster s effect, you can banish this card from your GY instead. You can only use this effect of Ursarctic Drytron once per turn.