Starting on May 18th, 2016, Dragonforged became fusible from combinations with Epic and Dragonforged Armors.
NOTE: As of mid to late February, 2017, all Dragonforged armors became fusable, by either combining two Dragonforged armors or by (very rarely) combining two Epic armors. Resulting elements from the combine do not necessarily match on the resulting armor. For instance, combining Malicious Ragemail (Fire/Water) with Keeper's Gemplate (Water/Earth) resulted in Swiftscale Regalia (mono Air).
Furthermore, levels from prior enhancement do not seem to carry over into the resulting armor (level 15 Malicious and level 12 Keeper's resulted in level 1 Swiftscale).
Initially only a few Dragonforged armors were fusable (see list below), however since all are now fusable, there is no need to update this list further.