We are about to come full circle

Several years ago, sustain via lifesteal/spellvamp was pretty insane. Those things were nerfed, but they were subtly nerfed more by poke comps going out of fashion in favor of hard engage comps. Hard engage was countered by disengage specialists (Janna, Soraka, Lulu, Alistar). Then the disengage champs got nerfed, several of the hard poke champs were changed, and the almighty burst era began.

Damage has gone up and up for several seasons, lowering time to kill and reducing the power of lifesteal by virtue of fights not lasting long enough for lifesteal to provide enough hp regen to live through anything, and now it has become a tool for champs that are ahead to stay that way because they're always full hp.

Lifesteal and sustain in the form of Death's Dance, the Domination tree, and the Legend: Lifesteal are making a comeback, and I don't necessarily think that's a good thing. Lifesteal has a few particularly abusive instances that should be addressed individually before lifesteal as a whole is considered for a buff, namely the effect crit chance has on lifesteal. Tanks already feel bad when carries get to the point they outheal the damage you can output, even through thornmail, and increasing that effect is not going to end well.

Of course, all of this is doubly relevant to our favorite bag of wind, Yasuo, who will benefit from lifesteal buffs more than probably anyone except for Draven. What do these champs both have in common? Crazy lifesteal scaling because of bonus damage on attacks that count as basic attacks.