Warden Attack: Life Drain

If I'm getting this right, the warden is supposed to be a scary, near-impossible to kill creature that players are supposed to avoid rather than fight. The problem with the warden I've heard about, is that once it detects you, it is basically just a bigger and stronger version of an iron golem, and iron golems are not hard to kill. All you need to do to kill an iron golem is to get it in a position where you can hit it, but it can't hit you (like standing on a four-block-high tower, or attacking through a hole in the wall). What is going to prevent players from just from just doing the same thing with the warden? If players could just kill a warden that easily, then the entire dynamic of the deep dark cave biome would be gone. Now for the idea. I was trying to come up with a way to make being detected by a warden always be a threat. The possible solution I've come up with is the life drain attack. The way the life drain attack works is, whenever the warden knows where the player is but can't find a valid path to them, a timer will start. If about 10-15 seconds pass and they still know where the player is, but can't pathfind to them, the warden will start draining the life from the player. When it is draining the life from a player, the player's life will start to rapidly fall at the rate of the wither 2 effect. When this happens, a beam would appear going from the player into the warden's mouth. This effect would ensure that players would always be watching for wardens.