Solak is a planned future boss that is aimed for release in March 2018. it is currently being developed by Mod Ramen. It is planned to be one of the strongest bosses in-game. A team of seven players are recommended, though there will also be a duo mode, which will cause different mechanics to take effect. The fight is expected to have "multiple health bars" in each phase along with sub-attacks that it will use alongside normal and special attacks. Planned rewards for defeating Solak include tier 92 dual wielded crossbows.
Solak is a creature of the Anima Mundi, like Vorago and Telos, and Guardian of Guthix who defends the Lost Grove from those who want its power. He is referred by the inhabitants of the grove as a "walker".
Solak is tasked in protecting an island that is inhabited by smaller creatures of the Anima Mundi. Guthix at one point had appointed Solak as a Guardian of Guthix. During the Second Age, Seren sent a group of elite elf warriors to aid Solak in his task. However, one of these elves became tempted by the power (the fairy Bub thought of the elf as pure darkness). Solak defeated the traitorous elf, though he became corrupted in the process.
Sometime after that battle, he disappeared along with the other walkers, hiding the grove from the world. During his disappearance the fairies tried everything to see him return, where even humans were said to have built temples worshipping him, which led the religion to die out as he never responded. The grove would not be in contact with the outside world until the fifth year of the Sixth Age. Solak is currently corrupted by a mental manifestation of the elf.
- It was revealed at RuneFest by Mod Pi that Solak was originally called Kalos.[source needed]