I would not mind seeing a divine defensive rune that would combine magic, skill, and physical defense. Another divine rune that would combine nimble and block would be very helpful to open more slots.
How about critical + dodge and hit rating + block?
Counterparts to Reliability.
And I also feel a trifecta defense rune for 200 fragments would be a great idea, especially given the 3 defense runes are the only yellows that can't go beyond 10.