Hello!
I've noticed that the EDK summon cannot attack large enemies. It is not just other dragons, but anything that seems to be large in any way, or oversized.
While very fun, the EDK isn't very strong to begin with, so this really does not help its usefulness. Especially since it does not last very long, I hope it becomes a big stronger out of the box as well, but being able to attack your enemies would be a good start!
So far I have noticed that dragons and large enemies like the Jotun King in Gyldenheim cannot be attacked by the EDK summon. I am still testing for other large enemies, or NPCs that are over-sized more than usual.
Thank you!
The Christmas Angel.