[{quoted}](name=Unlimited Chill,realm=NA,application-id=3ErqAdtq,discussion-id=5hHnLiRn,comment-id=0002,timestamp=2018-09-15T02:54:44.389+0000)
offers wave clear to champions that don't otherwise have it and healing at the same time. The AoE that is provided also applies %50 to lifesteal. It doesn't need to be combined with the deaths dance passive. Even getting rid of the passive AoE on it wouldn't be enough for the damage conversion and tiamat active.
I don't seem to understand what you propose for warrior though. Make it build out of tiamat or have lifesteal?
Tiamat would make it impossible to be built on champs like
and 
Giving it lifesteal would make any jungler that went warrior be broken. Each champ you put up there under jungle has no problem surviving in the jg and most of them have self healing. Also the jungle items already give sustain on them.
Ravenous Hydra is highly NOT recommended to be purchased, even on champions that it would be good with.
Most champions that buy tiamat in the first place are Jax and such. But they will never complete it.
Meta build currently -
and finally 
Essentially what I'm saying is most people that do buy Tiamat, will just use it to shove wave and do a fast recall. Then buy their normal core item.
(Meaning the initial 1200 gold investment gives much more gold to these champions, than rushing Triforce first essentially giving them more gold at the end of the day)
Even harder to kill
The item is relatively cheap (2900), if the player wants cooldown and goes BC or Ghostblade she gets popped instantly by the jungler, leaving top as a very easy tower first blood from 1 flash play.
Many Riven players will grab Death's Dance second or third, simply beause of how much durability it gives AFTER buying BC or before, But then she's behind in terms of shoving the lane for teleport plays, or will struggle to SHOVE lane fast enough for a recall in the first place (enemy laner with tiamat will clear wave and chunk your tower with the jungler himself)