It's random. There are 4 legendary souls at a time, but roughly 200 legendaries in the game. Why should exactly Fu-Shan's soul occur? Because you want that one? That's not how probability works.

yeah, 8 souls / day and statistically it should appear within a month at least once. 2 months already passed which makes me feel it is bugged somehow.

Would you mind running through some of those statistics?

put 200 white ping pong balls in a barrel, the number of legendary champs.  Paint one of them black, the one you want.  Now you get to draw from the barrel 240 times, the number of opportunities you have to pull the black ball.  BUT every time you pull, you have to replace the ball you pulled befo your next opportunity, sampling with replacement.  You have a decent chance to get the one you want at some point, but no where near certain.

But now say instead of painting the one you want, you number them 1-200.  Your assertion that statistically you should get "the one" you want now translates to you should get each and every one of those balls at least once.  An absurdly unlikely series of events!

Your odds are, in fact, considerably lower than the range one would attribute to the word "should":

https://www.dcode.fr/picking-probabilities

i

You would get a certain soul in 2 months for sure if the souls allready occured would not be seen anymore. But that is not the case. It's random and does not remember previous results. You are not "through" all other champs and now Fu-Shan has to occur, as the last one remaining.

Just pretend you don't want it and it'll appear, a bit like the invasion of mystery shards when trying to win artefacts.

Wish the Immortal Soul Essence was available to buy. Had a couple of characters come up in the Mystic Market I would love to have got souls for, but I'm too low level to farm the twins properly yet.

Based on the current legendary pool, and the number of champs you see in a day, there is a 50% chance you see any champ within about 15 days. As you go to a 95% chance to see a specific champ, I think it trails out to 75 days. That is to say it may not take 75 days, anything from 0 to 75 days is required to accumulate a 95% confidence of you seeing whatever champ you want in a refresh of 4 twice a day.

Basically, great chance you'll see the one you want again decently soon. And again after that.

How do you come to the 50% chance within 15 days? That's exactly the time period in krama's example (champs are refreshed twice in a day, he took 30 draws) and he came to a 14% chance.

Ok, the 200 legendaries where estimated, not counted, but is the pool really so much smaller that the chance jumps from 14% to 50%?

/edit:

I counted them, there are 207 legendaries in the game right now. My estimation of 200 was pretty good.

My gripe isn't the rotation, just the frequency of the soul essence, I do stage 15 every day with the six keys and usually in a week I get less than ten, most days its coin, I get its random but the drop rate could be better

I don't know about whatever internet calculator Kram is using, but the math is known and we can walk through it right now:

What you are asking is, given the market is unbiased each refresh, what is the probability of 4 champions having the champion in particular that I want out of 200. How many refreshes will it take?  So that is (in simplified terms) asking how many refreshes (n), would it take for:

P = 1 - (196/200)^(n) = some value acceptable like 95%.
(Binomial Distribution) https://en.wikipedia.org/wiki/Binomial_distribution

The value of n for 95% chance is ~150. Therefore, with two refreshes a day, you need 75 days or less to have 95% confidence of seeing the legendary you want. 

The confidence of 30 days is around 70%. The confidence for 17 days is around 50%, which I was doing mental math for when I said 15....

Lets examine that last statement:

P is the probability we see a particular result. Lets not even factor anything, and we'll just plug in a (n) value, which is number of events.

P = 1 - (196/200)^34

P= 1 - 0.503

P= 0.497

There is a 49.7% chance you will see a given legendary in 34 refreshes, which, with two refreshes per day means we have about a 50% confidence to see any legendary we wish in 17 days or less.

Further, looking at the calculator above, I believe Kram has it calculating as if you have 1 chance out of 200 per draw, when in reality you have 4 chances out of 200. 

So that is 30 total draws he has calculated there... which if you pretend that each draw is independent... you're looking at 8 total draws per day, 30/8 = 3.75 days worth of draws there for his 13.96% number.

But you can't do that either, since you don't get two of the same legendary champ in the 4 champs you see per refresh. You have to group the chance together as 4 in 200. Or, now that we've gotten some more legendary champs, 4 in 207.

Basically, that calculator above doesn't apply. See the actual math in my post above.

i

How cruel is this game... just one day before the nerf.....

You got what you wanted, be happy - it's a start. :)