Is there any idea of when this mode is coming out?
Nope, no release date estimated. We still got a lot of work to do.
We will begin on the troop trees, then troops and the items for the troops rather soon, if not it already started. Hopefully we can also start to work on the world map soon and it's locations, so the basic elements for the mod are then being worked upon. But also we will invest some more time in the crafting system, so you can craft your own weapons. We still plan to redo the sieges, but that is something for later. Also new companions and new quests will take a lot of time. But yeah, progress is being made, but as I said earlier, still a lot of work to do

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Most of the work though will be invested into the troops, world map, scenes and items I think. If we want it nicely balanced and provide an immerse Redwall experience for the players. And that is mostly a process of implanting, testing, evaluating, adjust, test, and so on until you get it as you want it to be.