Heroes to get Blade Mail against?

Verified. BKB blocks most non physical damage. As far as I can tell there are only two damage types in Dota 2: magical and physical. I don't think it's like all the WC3 Dota's where the system was built upon different damage and armor types.

Because of certain things I've come across, I think mechanics like Blade Mail and Cleave simply have exceptions to the basic rules. I think the term "pure damage" is no longer a type of damage but simply damage that does not face resistance. That's my speculation, but without confirmation from the devs or seeing the code first hand it'd be hard to know for sure. Some might say "But the tool tips say pure damage, so pure must be a damage type. Right?". Well let's analyze it.

For example, BKB gives magic immunity right? Yet most every ult can still hit you if BKB is active, you just won't take damage. Like for Enigma's or Necro's ult you wouldn't take damage but you'd still be stunned per their respective effects.

To add to all that I also ran a test. I attacked a target with a secondary target being cleaved.
The first set of attacks the secondary target uses BKB and takes cleave damage.
Second set of attacks the secondary target uses Blademail and reflects cleave damage.
Third set of attacks the secondary target uses Blademail and I (the attacker) use BKB and no damage is reflected.

Basically Cleave goes through BKB, Blade Mail returns Cleave, but BKB will block Blade Mail return on Cleave. Both the tool tips for Cleave and Blade Mail say they deal pure damage right? So why the inconstancy? Like I said before, I think they deal with exceptions to standing rules rather than make a new type of damage all together.

Here's the video of me testing this out. http://www.youtube.com/watch?v=rBLpX83stG4&feature=youtu.be

So Blade Mail won't go through BKB? That's interesting...and would also explain the Juggernaut thing. I was under the impressiont that pure damage went through everything, with no reductions.