Time Back is the way to go with armageddon, obviously. I suppose good astral resistances + ress stacks could go well as well, but with Time Back, it's way more viable.
Instead of Archdemons, though, I used emerald dragons. Timing it correctly, You can time them back in a way that also restores their Mana Drain ability, further helping with the 80 mana needed for Armageddon + Time Back.
I also got the rage accel perk from the Warrior Tree quite early, making me fill my rage with every armageddon cast, which makes for Charger + Awaken Dragon + Charger + Time Back, next round Charger + Awaken Dragon + Armageddon + Charger, then, again, Charger + Awaken Dragon + Charger + Time Back.... etc etc.
I had no problems using it since I thought of it myself, but it really IS a damn cheap tactic
~Sylv