Give PVE players an endless game mode, like the counterpart for RTA for PVP. Make an endless automaton tower which requires no energy or currency to enter and could be played repeatedly with no limits. Per floor would give random buffs and the higher the floor, the harder the enemies will be. Leifs or charms could be the reward or an exclusive border/emote by reaching a specific floor.

The Endless Tower could be unlocked upon finishing floor 25 of the regular automaton tower. Ranking will be based on the highest floor the player can reach within a run. You can make it that units can't be revived by stigma and the 4-unit team couldn't be changed until all units are dead or the player yields. When lost, the player would need to start again from the lowest floor, but their highest floor would be recorded.