Better fix might just be to put a tile of dirt floor somewhere behind it so construction + outpost can be used to force entry.

Hi Steve, I designed Smoulder so I was a little confused (at first) why it wasn't working for you. I just tested it myself on the internal build and it seemed to work fine for me however that lead me to remember that recently we fixed a bug where the shield was being removed from objects visually but the actual invincibility wasn't removed, which im guessing is the problem here. Obviously that bug has been fixed internally but still exists on the public build.

That being the case i'd expect the issue to resolve itself once the next patch is released with that bug fix in. 

This is part of the stalemate mechanic. You need to own more Underhills than your opponent to deal damage, equal amounts cancel each other out.

Hi Tom, this was actually a late (really close to release) temporary "quick fix" to solve a bug where using the custom theme stuff would break the Locked players AI. The devs are aware of it and should be taking a look next week when they're back in the office.

The Pet Dungeon Toolbox and Gateway are only available in My Pet Dungeon mode maps as they are incompatible with many of other features of the game which are available in other modes.

Spirit Workers have the ability to "teleport" gold straight to a vault (like a Gold Vortex does), so the gold is actually just being instantly transported to the vault as soon as their backpack is full.

Suvius shouldn't be able to be imprisoned afaik, that's probably what has caused this error to occur.

Just to check, you did finish/complete the level after finding the artefact right? (Rather than immediately quitting after using it)

Could they have originally been random artefacts (The ones placeable in the map editor which spawn as a random one each time), this could be an unexpected case where they have been removed but can still be spawned via that randomness?

The artefact completes the "channeling" part of a ritual, which for most rituals is the full preparation process of the ritual, in the case of the Summon Vampire ritual, it only completes the first 50% which is usually channeled by cultists so you will still require the 3 sacrifices are normal.

Put simply, with this particular ritual (since it differs from the others), the artefact will get you from 0-50% instantly ready for the sacrifices to be made.