User blog comment:Degritone/Wae, the Density Manipulator/@comment-7709681-20150117172830/@comment-25364408-20150117180719

He doesn't have a slow or passive while invincible. The passive damage also does not deal additional damage to tanky units, it's based off his health, not theirs. Should I make this more clear? Also, the passive slow only applies while he has 25+ density, or, without his ally cast Q or his R, 2500 bonus health. This is also lost when he uses enemy cast Q or W.

Allies can still get hit by projectiles, they just have to be standing in the right spot, or in the 300-500 range while projectiles are orbiting him. Imagine how devastating Ezreal's ult would be to teammates if it got in orbit.

No, he cannot, as it still, technically, requires targeting the ground to use. He cannot target while in W. It's Vlad's W without the damaging or speed gain effects, with the ability to pass through terrain.

There is no way to "replete the secondary resource," as it defaults to after any manipulation has ended. Meaning casting his Q on an ally only temporarily increases his density, and all abilities reverting his density to his default upon ending.