Re: counter tresdin legion commander
There are some heroes that can be a real counter for him. Huskar and Axe, perhaps centaur (not sure if returns works here, but +15/30/45 str surely works).
He cannot duel any of these heroes, and if he duels a teammate, they can stop him (Life break, Battle hunger, stun + double edge). Some anti-dsp can work as well (tiny, pandaren, razor if he can ulti or static link).
High armor is a good counter as well.
The poins is that LC can counters many int heroes if he has mobility, but does not do much thing against tanks.