Given that fulings appear smart enough to form communities and build villages, what about a late game event where Fulings attempt to get past the standard trench and raised earth defenses that pretty much mob-proof a base? The methods they use might scale depending on an aggregate of player's skills or how late in the game they are. The most basic tools could include groups of fulings running up carrying ladders or boards to get past walls and ditches.
Alternatively you could get an alert during the event that a group is attempting to get past your defenses, then you have to find the fuling(s) that are in the process of building a ladder or bridge.
If a player has high enough levels of combat skills then perhaps they could even wheel in one or two small siege engines to smash a segment of wall before they charge at it. Like I said the number of fulings or groups with ladders/siege engines could scale with player skills but also the number of players within a certain radius.
It seems like it is pretty easy to mob proof a base even early on so I wouldn't mind seeing the occasional greyling trying to just climb a wall.
Let me know what you think or any improvements that might be good.
Source: https://www.reddit.com/r/valheim/comments/uegpv0/siege_events_to_counteract_mobproof_bases/
