Im actually thinking Edge of Night might not be so gamebreaking.
If you take any damage while channeling it the item goes on CD for around 6 seconds. So its completely useless to try to use the active effect while team fighting. The only real use its active would be to flank with the spell shield up/ use it to protect yourself from a flank, or try kill a guy who is on top of a ward. It doesnt really screw over most champions anyway. Just
, Maybe
and
depending on how long their ult marks last and the interaction they have with spell shields when they pop and deal the damage, also assuming you get away from them so they cant stop its activation. I think new Duskblade is alot worse then Edge of Night tbh.
Just mash that shit any time its up because....maybe something. The cooldown is so low its up by the time it is down. Also, it is completely overlapping the niche of Banshee's Veil. Gamebreaking or not its a horrible idea.