Should I Kill Odahviing?

Since Odahviing cannot be killed, there is no point in trying to fight him or trying to drain his power. Instead, he can be immediately lured into the enclosed area, and the trap will come down on his neck and hold him in place.

Can you ride Odahviing again?

While at his maximum level he has the same status as an Ancient Dragon. You are able to ride Odahviing with the Dragonborn expansion. ... However, it is also possible to keep him around long enough to use Bend Will after using Call Dragon.

Should you kill Paarthurnax?

Solution: Attack and kill him. This will cause the quest to reappear in the journal. However, in some cases Paarthurnax will remain invincible even after the quest has disappeared, preventing further progress in the Blades storyline.