Update: the Necromancer faction is back, a few "offending" sprites are still missing but will be replaced soon.It has come to light that some graphical assets in KeeperRL infringe 3rd party copyrights. I wasn't aware of this, as these were made by someone hired for sprite creation recently. This is very bad news and all assets made by that person have just been taken down from the game.
Unfortunately this includes the whole Necromancer faction, which is now unavailable in the game starting menu. Saved Necromancer games will still load, but a majority of sprites won't be displayed. If you have a Necromancer game in progress I suggest waiting a few days until we sort it out. Other factions should be playable outside of an occasional missing sprite here and there.
In the next few days we will figure out exactly which assets are non-original and add replacements for them, and everything should be back to normal.
I am terribly sorry for this blunder and inconvenience to all players. From now on I will make sure to have a 100% certainty about the origins of new assets.
If you have any suspicion that a KeeperRL asset may be "stolen", please get in touch, but also keep in mind that some older sprites come from the
16-Bit Fantasy sprite pack by oryxdesignlabs.com and you may see them in other games.