Getting the bounty troop from legendary to mythic, I usually throw 25k keys to get halfway then use daily offers to top it up. The pool is very diluted.
But there’s only going to be, what? 5 troops in the event chests? Throw 50 of those to top it off if needed.
IIRC you need 190 copies to fully ascend a common.
A single gold chest has a 48.75% chance to drop a common.
There are currently 109 common troops in the game. (Not all of which can be obtained from chests)
I’m no good at math, so take this with a sack of salt. I think the probability of you having obtained enough copies after opening this many chests should be:
If I’m short on Gems and using Gold Keys, I work on an average of 2 Gems for every 200 Gold Keys, although (if I could be bothered to do the maths) it’s actually more like 1.8 - 1.9
Thank you for the helpful responses everybody. Between gold keys and blue task, I’m optimistic I’ll have enough gems to fully ascend Hawthorn without spending a blue orb
I gathered info while collecting “Ogress” for mythic ascension (85 copies) .
I spend both gold keys, gold and other keys.
For 50 keys (or 15k gold) avarage was 0.84 gems
For 85 copies 114k Gold keys