I've been curious as to why bloodlust was so good prior to patch 6.1.

I mean you usually get your first 2 crit items around mid game where teamfights are more common to happen and having that heal and AS steroid without having to have an item take up a slot for it is nice. And around this time, ADC's usually hit level 8, 9 or 10.

But since it's heal has been changed to scaling in patch 6.2, it has seen a heavy decline in use.

With the scaling in mind, you would reach it's pre-patch 6.2 healing at level 10, or even 9 to cut it close, but you now have that 30% AS steroid at all levels instead of 20%. And again, that healing is useful in terms of itemization since you "have" a source of lifesteal, meaning that you don't need to rush BT at the moment. Of course this would only apply if you are rushing crit.

Then again, it's main contender, Fervor of Battle, sounds more like a consistent and dependable source of bonus damage compared to a crit-based heal. Would this then just limit Bloodlust to a few carries that need to rush crit or is crit too risky of a stat to bet a keystone mastery on?