As said in topic, I’m not sure what to do regarding holy tanks and their rating.
My options are
Onatel +10 or Rana + 11.
With the new rating (put in ref to guide) both of them are B.
My team is:
Evelyn, Kageburrito, Onatel/Rana, Magni, Marjana.
If I use Rana tank I get to free up emblems fro put on Proteus and Kiril.
If I use Onatel tank I can buff my Wu for titans.
Our priority in alliance is war >= Titan > raid defense.
Helps pls?
Moo out 
Use Onatel, but keep emblems on Rana. No need to put them on Wu.
Don’t remove emblems from either of them.
Onatel can be your war tank.
Rana should probably be on your reg defense.
Onatel works great offensively and defensively.
In my honest opinion, Onatel would be your best tank. That is the hero I currently use.
Good luck
Bless you my little one, But Onatal should be your choice
Onatel for sure.
But have you asked your alliance, and they should be helping you too 
I’d note one thing not said yet. The rating is a “guide.” You have to understand your own deck and how you like to play. Just because someone says “this person is the best,” others may disagree.
It’s a good guide, but remember, it’s a guide.
Im not as familiar with Rana as she is rare and not in my deck. But Onatel is solid. I primarily use her on offense though. She is on my defense too, but not featured as a tank.
Rana over Onatel for tank.
Onatel is amazing flank, not so good as a tank. I have only lost once I think against her on tank position.
Even Elena has better success.
Onatel has to live at least 3 better 4 turns after the cast and as tank she won’t often. Just keep throwing tiles at her and hoping that she won’t cast again. Then she becomes really hard and it will be hard to recover from her special.
My vote goes to Rana. Her ailments are creepy annoying and even can’t be cleansed completely.
I vote onatel and 20 characters.
I haven’t faced Rana enough to have an opinion of her as tank myself. In raids I find Onatel much more difficult as flank but for wars over six teams she is very effective as a tank. She should easily be able to get firing in the latter half of the war and once she does she is very hard to stop.
Rana is very underestimated. I don’t agree with the B rating at all. Same for Onatel. Both are excellent tanks as they can absorb more than 3 tiles from a mono attack with only a few emblems.
I would put Rana over Onatel as I have a better chance of surviving an Onatel cast.