Zubababa Knight - Duelist's Advance (DUAD)

If this card is Normal or Special Summoned: You can activate 1 of these effects;
• Add 1 "Zubaba" monster from your Deck to your hand, except "Zubababa Knight". This card's Level becomes that added monster's Level.
• Destroy 1 Level 4 or lower Defense Position monster your opponent controls.
If this card is detached from an Xyz Monster to activate that monster's effect: You can add 1 "Gagaga" monster from your Deck to your hand. You can only use each effect of "Zubababa Knight" once per turn.