Official merchandise I think I bought at either the Black Flames of Blasphemy VI Warm-Up (November 2015), the festival itself OR two years later at SteelChaos (November 2017) - both events were held at Nosturi (RIP) and had a lot in common. Like D666. Over the years this stuff kind of blurs together. Anyways, I remember I got wrong size first and had to go back to swap to the correct one.
Prints on both arms, chest and back, Just Hoods by AWDis is the brand. 80% cotton, 20% polyester. For some reason, I've worn this quite a bit while going to work and gym.