Nike has sued a small Brooklyn-based studio for releasing a modified version of its sneaker that contains real human blood inside its soles. Nike filed a federal trademark infringement lawsuit against MSCHF Product Studio over the release of a Nike sneaker called “Satan Shoes” developed in collaboration with rapper Lil Nas X.

The pair of modified Nike Air Max 97s features a pentagram and a reference to a Bible verse talking about Satan’s fall from heaven. While those are arguably already controversial features, the weirdest feature of the pair of Nikes is that it contains real human blood inside its soles. MSCHF said that the blood was taken from members of its design team.

The Satan Shoes were released on Monday and quickly sold out in just a few hours. MSCHF released a total of 666 pairs priced at $1,018 each.

In its lawsuit, Nike said that MSCHF had infringed and “diluted” its brand with the release of the modified shoes. The company said that it had released a lot of complaints from people thinking that it was involved in the creation of the shoe design.

“In fact, there is already evidence of significant confusion and dilution occurring in the marketplace, including calls to boycott Nike in response to the launch of MSCHF’s Satan Shoes based on the mistaken belief that Nike has authorized or approved this product,” Nike said.

The pair of Satan Shoes were created as part of a promotion for the music video for Lil Nas X’s new single titled “Montero (Call Me By Your Name).” In the video, the rapper is seen falling from heaven and then at one point, he is shown giving the devil a lap dance.