Ashaya is definitely one of the hardest cards to evaluate in Zendikar Rising. It has all the markings of a format breaker. But at the same time, it's too expensive at 5 mana.
It could be a solid replacement for Nissa, Who Shakes the World after standard rotation because of its ramping effect, but this only applies to non-token creatures, making things more complicated.
The general feeling for this card is good, but there just isn't enough information for it to be a solid investment right now.