I don't think people like being robbed out of a kill like that. If you are struggling, I think a lot of existing items in the Vitality category can alleviate this problem.
With the way this item is laid out, I disagree. There's a very high 5 minute cooldown between each time it goes off, it requires other players to do
a lot of damage that can only be achieved by an enemy team that's much further ahead than you or are taking you out by surprise, and you can still kill players who use this if you're able to shoot or use your abilities in their general direction.
This item is pretty much like Haze's smoke bomb already, but you cannot use it offensively.
The current items in the vitality category don't provide a way to ensure survival for weaker players, as pretty much most of them only provide protection against a few attacks, that can be seen as nothing for the enemy team. Let me demonstrate what I mean by this, by looking at the current items:
Enduring Spirit, Extra Health: 75/125 extra health. That can protect against what? A single low level pocket cloak? The pocket can still teleport to your location and shoot you point-blank, and if they're doing good; they'll even have more items that will probably do more than what this item is trying to protect against. A lot of the T1 items are incredibly weak when dealing with players who are snowballing very early.
Extra Stamina, Spring Boots, Extra Regen: Completely pointless if the enemy team has a way to slow you down or keep you in their range for an extended time. The 1 or 2 extra health points that get regenerated every second do not contribute to you surviving a flank, it only helps you
after you've escaped. So again, not helpful.
There is an argument to be made that maybe you could rely on T2 items like Bullet Armor, Combat barrier, and especially Divine Barrier. I would agree with that, but this doesn't help players who are hard stuck at the beginning of the game who are unable to gather enough souls to buy these items, and I think rushing Divine Barrier or a Reactive Barrier just because you
think you might have a hard game early is not an optimal solution.
Edit: Added clarification on why I think other vitality items aren't great for struggling players.