Time Demon?
time demon (2) | Spd: 6 | HD:17 | HP: 105-149 | AC/EV: 11/10 | Dam: 40 | demonic, doors, see invisible, lev, regen, !sil | Res: magic(98), elec, rot, neg+++, torm | Vul: holy++ | XP: 1933 | Sp: b.time (3d10), slow, blink close, dig esc: Time.Travel | Sz: Large | Int: high.
Bolt of Time - Beam targeted slouch. Ignores AC; uses your move speed/its move speed as your resistance. Average speed characters take (1.6 x 3d10) [similar to Hellfire]; hasted characters take (2.5 x 3d10) [Brutal]. If you are slower than it (affected by its slow or use slowing on yourself) it does no damage; but this guy isn't to be trifled with in melee either.
Time Travel - Enemy version of Step from time; after 1d5 turns; {foo} disappears for 5d10 turns and returns in the same place with no healing. You can wait it out if you want the XP/to be sure it is dead or just keep on your way. Effectively it's a similar escape spell to Tele Self.