The answer to beating Earthspirit this international is actually Pudge
Earthspirit appears to be the best hero of this international. I have about 1500 Earthspirit mid games and I promise you mid Pudge is the worst matchup I've played this so many times and always feels rough heres why.
Earthspirit does not like vsing tanky cores, Pudge is ridiculously tank with infinite str scaling and high magic resistance. In lane Pudge has about 15-25 damage advantage last hitting if he goes double bracer phase boots instead of bottle. Pudge will not die by a cheeky roll into kick back into tower if he has 1 point of flesh heap. Pudge can just sit on the wave denying everything if Earthspirit uses kick to secure range creep that's a huge window to kill ES as your defense if you get hooked is kick Pudge away, you won't be able to roll away from a Pudge on you especially if he's already got phase boots, dismember + any other disable is usually enough to stop magnetize, Pudge takes literally 0 damage from magnetize if he has 4 points in flesh heap ( level 3 magnetize does like 5 damage per second ) he does not give a shit about urn + magnetize even vessel tickles him when he has flesh heap going. Earthspirit play style yoloing into the middle of a team fight Pudge will just sit on you taking no damage melting you with aghs + shivas.
So yeah mid Pudge + another tanky core like Lifestealer is aids to vs. Some other heroes are a pain in the ass for Earthspirit but they've been over nerfed or just bad: abbadon, legion commanded, qop, Huskar, omniknight, oracle, monkey King, quas wex invoker
Slark/ jug sounds good in theory because you have dispell but really Earthspirit just kills them by existing next to them they are too squishy.