What is your suggestion?: Introduce either a permanent game mode. If that is not feasible, make it temporary and let it be a competition similar to releases of Mobile and HCGIM.
Is this in OSRS?: Yes, as a RL plugin I believe.
Has this suggestion been accepted already?: No.
How would this benefit Alora?: Would just be a fun and unique experience and I believe it would draw in some new players. Also fill the gap until next Leagues.