User blog comment:MickB/Sla'arth, the Ancient Vigilant/@comment-11434673-20131031025538

Ice Typhoon: How many times does the damage tick? Once every 0.25 second for 1 second (4 ticks), cuz otherwise this damage shouldn't be "Over time" but "Magic damage". Also, I think the slow at the first three levels is too weak. I would rescale the slow (start at like 18 and increase by a few points each level), over the 5 levels. You should also think about reducing the duration of the ice area, down to like 2 seconds (3 seconds is pretty OP considering you have ways to keep them in place outside of the slow). Also, increase the mana some. Its a tad low for an AoE damage and slow.

Chilling Area: This ability's damage should read "damage per second" over damage over time. It only deals damage to them while they are on the spot? If yes, it should read "deals magic damage each second an enemy stays in the area". (DPS) If no, it should read "deals magic damage over three seconds". (DoT) Also, I think the root's duration is a bit excessive for an AoE. You should reduce the root to a flat 1.25-1.75 seconds.

Lethal Frost: Passive: It is pretty OP. Does the passive stack the defenses each time he deals damage? Also, the 25% should be reduced (it gives way too much free defense just for playing offensive) because for every 100 damage he deals, he gains 25 armor and MR. Active: I think the damage is too high at all levels and should be reduced. Also, the cooldown is also too high pretty much through all but the last 2. You should reduce the cooldown (10/8.5/7/5.5/4). It feels like the root is in there to make it less like Ezreal's Q. Care to explain why?

Arcane Imprisonment: Meh. The effect is pretty OP (increasing all... ALL damage dealt to the target is not a balanced thing) but it is literally Lissandra's ult but instead of dealing damage, it makes them take more. I think you can think of a better ult to take its place (and I would hope you would).