Spiritborn passive Adaptive Stances is very weak and is not used by anyone. It would be better if the passive gives movement speed for eagle abilities, damage reduction for gorilla abilities, damage for jaguar abilities and maximum health for centipede abilities. But most importantly, gaining these percentages should increase these values by a certain percentage per dexterity we have instead of increasing our core stats. And if both values can be applied simultaneously, it would be more useful and work well with our primary spirit hall selection. For example, I can use any jaguar ability as my main damage ability and choose gorilla ability from primary spirit hall and gain both damage reduction and damage at the same time. Of course, there can be a maximum of 2 bonuses for balancing and these bonuses can last as little as 4 seconds. Anyway, my recommendation for this passive for season 8 is:
Using an eagle ability gives 20 percent movement speed,
Using a gorilla ability gives 20 percent damage reduction,
Using a jaguar ability gives 20 percent damage,
Using a centipede ability gives 20 percent maximum health bonus.
These bonuses last for 4 seconds and you can have a maximum of two bonuses at a time.
These bonuses increase by 20 percent of the dexterity you have.
This is the main idea, of course you change the values for game balance.