Heretic-to-Hexen by deathzero021 is a mod for Hexen that brings Heretic's maps to Hexen. Maps were heavily modified to work with Hexen assets, as well as containing new features from Hexen and new map progression. All weapons and enemies have been modified in an attempt to balance the experience due to the differing map designs between games. Currently only the first episode is complete, although the other episodes are included in the menu and in the mod, they are not playable. The mod will be updated episodically as he completes them but it may be a while before Episode 2 is complete. For the first episode, check the development thread over at Doomworld.