Warlord's bloodlust is easily the most problematic effect on balancing in the entire game right now.

Giving champions a bloodthirster at level 1 is really overdoing it, and while I understand it only gives that huge lifesteal at low hp, that's the only time it matters, lifesteal means nothing at high hp and that's why Warlord's is insanely strong even with the diminishing lifesteal with hp effect.

Bloodlust allows for ANY adc and ANY support to have an easy time farming and a far stronger early game than anyone who doesn't take Bloodlust. Champions who were meant to be weak to poke like Vayne and Kog'maw can heal it back and crush you in an all in without ever buying lifesteal items. It means you can pick Thresh and Vayne and have a hyperscaling botlane with a fairly safe earlygame. I think it's the real reason Vayne is so strong right now, not because of the tumble buff, or shiv, or PD. I also suspect Janna wouldn't be performing so well without it, because she can miss multiple shields on her ADC only to have them lifesteal the poke away with Bloodlust.

I think it needs to be removed or reworked. It doesn't allow for healthy counterplay or fix anything, it just amplifies weaknesses and strengths. ADCs still explode when focused but now they can duel at nearly any stage of the game or take a turret after winning a trade with 5% hp left because they no longer fear being cleaned up by the jungler.