Photon Butterfly Assassin

Once per turn: You can detach 1 Xyz Material from this card; change 1 Defense Position monster your opponent controls into face-up Attack Position, and decrease its ATK by 600.

Discuss, Also ive noticed that the "2 Level 4 Monsters" is not here on DN. Strange.
This card has won me a game against gatekeepers, along with N50: Black Corn.

This could work with Asura Priest, from seeing one of the most recent posts

Whoever created Number 50

Thx you, althought it cann't defeat stronger monster, but you can SEND Gantestsu and Zenmaines to grave

Similar to Evigishki Merrowgeist. Descent Black Rose Dragon-ish effect but you should only run it if you have space. And Extra Decks are cramped nowadays.

is playable, i run it on some decks and works well, but as said by goodtimes, you need space on your extra deck, and i only have it on my crystal beast deck