Ash's shield is very small and easy to avoid(it can even go throught you ) , when you buy cc immunity item(she will try to move you character), you can easly rush throught it and make it useles, then u can easy deal damage to her and finaly kill
Ash's Shoulder Bash ends upon hitting a target. Try to block off her most convenient escape path when she reaches low health, trading 800 health for a basically guaranteed kill.
Getting pushed back by ash to the edge of the map? Androxus' Nether step can counter this because ash can't push you very far away. So can Buck's Heroic leap, Evie's Soar or Drogoz's Jetpack
During Ash's Ultimate ability she is not CC Immune, Makoa can Dredge Anchor her out of her area and Bomb King can stun her with Grumpy Bomb. If she has the Battering Ram legendary she will use this to escape the stun and therefore be out of the area!