If Cthulhu is killed, his body immediately fades away into a noxious cloud of otherworldly vapor that fills an area out to his reach. This cloud blocks vision as fog cloud but can't be dispersed by any amount of wind. Any creature in this area must succeed at a DC 26 Constitution save or be poisoned for as long as it remains in the cloud and for an additional 1d10 rounds after it leaves the area. Cthulhu returns to life after 2d6 rounds, manifesting from the cloud and restored to life via true resurrection, but for 2d6 rounds cannot take reactions and can take either an action or a bonus action on his turn but not both. If slain again while he is suffering from this effect, Cthulhu reverts to vapor form again and his essence fades away after 2d6 rounds, returning to his tomb in Rï¿1/2lyeh until he is released again.