When fulfilling the cost for ‘Soul of the Supreme Celestial King’, which is to tribute 1 Spellcaster Pendulum Monster with 2500 original ATK, you can’t tribute face-down monsters, even though you hsould be able to
Bug reproduction steps
- Summon a fitting monster for the cost, such as Supreme King Gate Magician in Face-down DEF or flip it face down
- Try to activate ‘Soul of the Supreme Celestial King’
You should be able to tribute a fitting face-down monster, as confirmed by the famous ruling regarding ‘Icarus Attack’ and a face-down Winged-Beast Monster. Once tributed, the Type, original ATK and status as a Pendulum Monster can be checked.
What OS are you using