Hellfest is making its return to Clisson from June 18 to 21, 2026. As always, the extreme-music festival is pulling out all the stops, filling the lineup with a wealth of talented artists that will let festival-goers cut loose. So, who are the must-see acts on stage this Sunday? From Napalm Death to Pennywise, with Acid Bath in between... Here are 5 bands you can’t miss this Sunday, June 21 in Clisson, for the fourth and final day of Hellfest, 2026 edition.