He is certianly on the list of heroes to get reworked. I hope to get to him soonish.

my friend have been spamming since he discovered him.
His Strengh is to be able to move across the map without any help and at will.
Level 25, he got no cooldown for his Teleport, this is where he shine. At this point he will got no cost and no cooldown for his teleport, and he got 0 sec cast-time.
So when your teammates are in danger, you just could tp in 0 sec across the map, Wait the bosses to come, then tp back to revive them + his treant are a threat source. his Q is really good in early phases and his R is great against Slardars and death prophet.

So he might get a rework in damage department but i really think he is at least viable

true since EBF has to need to "push" maybe the concept might be as an ambulance, but as carry its confusing and we will find some issues here, since he too rely on treants and Q, if the treants are cut down and change with dmg skill, the Q is useless. if R not replace then the agh should be rethinking. if the treant get buffed 3 hits that are too low not inculde wipe out upon insta kill skill boss like magma, necro arrow,doom razes etc.