Waaaaaa...
I love Kija's transformation sequence. It fit his character so perfectly. Whereas Shin-ah and Jeha both seemed to be "consumed", Kija embraced this new power. It was lovely.
Now, as for Zeno being the bad guy - I really feel like that's a red herring. It feels too much like "bait".
If it actually happens that he
is the big bad, I will be very surprised. My guess is that this preserves the dragons. After all, were they to die, their powers would be passed on the the next person. Could that be used in a selfish way? Sure! I just don't see Zeno as so desperate a character as to hurt his newfound family.
But it is rather odd that, despite holding the chalice, Zeno's regenerative powers are not working...