Dawnbreaker/Counters

Bad against...

 * disables Dawnbreaker's and she's a melee hero.
 * and slows down Dawnbreakers's movement speed so she's unable to get out from  (unless she has  or   ready to use to escape, besides the ulti however,  chasing her down is going to be easy due to the slow).

Others
List of heroes that counter Dawnbreaker, and list of heroes that work well with Dawnbreaker.