The League of Villains, specifically Shigaraki had grown fraustratied at being beaten by the heros over and over agian even with nomus.

So, they decided to call for backup. Toga had gotten some blood from Dabi to put on a pentagram that was drawn on the floor with blood that Toga had hunted down from civilians.

Shigaraki was sitting on the bar stool with Kurogiri opposite of him. Spinner and Mr. Compress were watching the scene from the back as Dabi and Toga stood beside each other, putting a drop of Dabi's blood on the pentagram.