Okay, so here's a take on the lich as a 14th-level elite. It's a controller with themes of cold magic, illusion, and mind control. I suggest that it command a group of skeletal tomb guardians and perhaps a couple of vampires, or some homebrewed undead in the level 9-12 range:
LICH (Level 14 Elite Controller Leader)
Hp 210, Bloodied 105
AC 28, Fort 26, Ref 24, Will 29
Speed 6
Resist 10 necrotic, 10 cold, +2 saving throws; immune poison, disease; vulnerable 5 radiant
Action Points: 1
TRAITS
Deathly Chill: Necrotic, cold. Aura 3. Any creature that enters the aura or starts its turn there takes 10 necrotic and cold damage.
Chessmaster: Aura 20. At the start of the lich's turn, it can slide all undead allies within the aura up to 2 squares.
STANDARD ACTIONS
Deathly Grasp (Basic, At-Will): Necrotic, cold. Melee 1, +18 vs. AC. 3d8+10 necrotic and cold damage.
Icy Blast (At-Will): Cold. Ranged 20, +18 vs. Fortitude. 3d8+20 cold damage and push the target up to 3 squares.
Searing Hatred (Encounter): Psychic. Ranged 20, +18 vs. Will. Choose one of the target's allies. At the end of the target's next turn, if it did not use a standard action to attack the chosen ally, the target takes 30 psychic damage. The lich can repeat the attack as a minor action to sustain the effect. The effect ends if the target or the ally is reduced to 0 hit points.
Wall of Ice (Encounter): Cold. Wall of up to 8 contiguous squares within 10, +18 vs. Reflex. 2d8+10 cold damage and the target is restrained (save ends). Effect: Affected squares are filled with a barrier of ice 20 feet high that counts as blocking terrain until destroyed. The wall as a whole has 50 hit points, immunity to cold, and vulnerability 5 fire.
MOVE ACTIONS
Dark Resurgence (Encounter): Teleportation. All slain non-minion allies (including undead) within 20 squares are revived. They are now considered undead and minions; they have 1 hit point each, are immune to poison and disease, have resist 10 necrotic, and take no damage from missed attacks. The lich then teleports up to 20 squares.
MINOR ACTIONS
Crushing Terror (Encounter): Fear, psychic. Close burst 5, +18 vs. Will. Until the end of the lich's next turn, the target takes 20 psychic damage the first time it attacks the lich or moves closer to it.
Spectral Harbinger (Daily): Illusion. Ranged unlimited, line of effect not required. An illusion of a Medium-sized humanoid creature appears in a square of the lich's choice and lasts until the end of the lich's next turn. It has defenses equal to the lich's, but any attack which hits the harbinger destroys it. The lich can see through the harbinger's eyes and can sustain it as a minor action.
TACTICS
The lich uses Searing Hatred to make a melee enemy attack a weaker ally, then holds its foes at bay with Icy Blast, Wall of Ice, and Crushing Terror. When its allies have been destroyed, it uses Dark Resurgence to revive them and reposition itself. Spectral Harbinger is used to harass enemies from afar, or to cover the lich's retreat if the battle turns against it.