Ballista and towers.

Here is the most accurate answer:

Moreover, even if your hero has the Artillery skill, or is even a specialist in it, you only direct who to shoot at, but the damage doesn't increase... although sometimes it happens that the damage is written as 160, but in reality it will be around 70...

Regarding artillery: I had a situation where a ballista (artillery) killed 3 devils, although the hero was quite decent...
And as for towers during defense: there were times when they dealt almost 5000 damage!!!
P.S. At first, even my friends didn't believe it, until I showed them the save file...:)