All Fiend-Type monsters you control gain 500 ATK. You can target 1 "Archfiend" monster you control; banish 1 other Fiend-Type monster you control, and if you do, Special Summon from your hand, Deck, or Graveyard, 1 "Archfiend" monster with same Level as the targeted monster. You can only use this effect of "Archfiend Palabyrinth" once per turn.
Have 2 b skulls and was curious so I tested it. This 100% works, under the card effect. You cannot summon from the extra deck, only the graveyard, so it ~technically~ works. If you have one b-skull in the graveyard, and summon a second one, you can use palabyrinth to revive the dead one, that's it. Anyone know of possible future cards that would allow you to discard from fusion deck?
I just run a standard fiend deck with cards like dark necrofear, but i also run beast of talwar and summoned skull, insane combo, basically, as long as you have one, and fiend monsters in your deck, they will ALWAYS be on the field.