Once someone buys Thornmail you can't touch them, at all. You do so much damage that it just kills you, especially when a mage buys it, because they build magic pen.
It either needs a weaker variant for Dominion, or it needs to be removed.
Going off on this tangent, the only hero that it was actually practical to build Blademail on was Axe due to his taunt, but you needed some way to get into the middle of a crowd before you could use blademail effectively. (So you also needed to build a blink dagger). Otherwise, blademail was usually not practical unless your enemy isn't paying attention (which doesn't happen at higher levels of play)
As a direct extension of that, if Blademail was somehow miraculously imported into LoL, I think that the only champion that would really benefit from it would be Galio if he popped blademail right before flash and ult. Some other heroes that are frequently first targeted due to their initiation skills it might also be beneficial on (to stall for time) such as Amumu and Morgana, but that's just my thinking.
Hint: activate LoLBlademail, step on Teemo mushroom
Tryndamere is doing a lot better now, but...
It either needs a weaker variant for Dominion, or it needs to be removed.
As a direct extension of that, if Blademail was somehow miraculously imported into LoL, I think that the only champion that would really benefit from it would be Galio if he popped blademail right before flash and ult. Some other heroes that are frequently first targeted due to their initiation skills it might also be beneficial on (to stall for time) such as Amumu and Morgana, but that's just my thinking.