If this card is Normal or Special Summoned: You can discard 1 card; apply the following effect, depending on the type of card discarded.
●Monster: Add 1 Trap from your GY to your hand.
●Spell: Add 1 monster from your GY to your hand.
●Trap: Add 1 Spell from your GY to your hand.
You can only use this effect of "Mystrick Hulder" once per turn.