How do you make Valkyrion playable? You don’t play the card as written.
Delta the Magnet Warrior
You can only use each effect of “Delta the Magnet Warrior” once per turn.
(1) If this card is Normal or Special Summoned: You can send 1 Level 4 or lower “Magnet Warrior” monster from your Deck to your Graveyard.
(2) If this card is sent to the Graveyard: you can banish 3 Level 4 or lower “Magnet Warrior” monsters from your Graveyard, except “Delta the Magnet Warrior”; Special Summon 1 “Valkyrion the Magna Warrior” from your hand or Deck, ignoring its Summoning Conditions.