The answers is probably tucked in a thread or three already, but I will fire away.
The 3 immortals u can get is on a rotation every week, so next week there will be 3 other swapped out u can get? (Not talking about the featured one.)
If you already got 2 of the weekly immortals, but not the 3rd, the chances getting the 3rd becomes as good as it was getting the two others - since you can just get each of them one time?
What are the chances of getting the featured one, a weekly one and the Icons?
The odds can be found in game. The odds for the one you want will be 1/3 of what’s listed for random weekly Immortal. I can’t speak to whether you always get 3 different immortal each week, it might be possible to get a repeat in back to back weeks if the previous week was the end of a cycle.
The random weekly immortals don’t stop showing up until they’re capped at Level 30.
After that it really !#%#^#$#$%# sucks as further Level 30 Immortal souls refund Burning marks in Epic Chest refund rates (15 Souls→3 BMarks, 30 Souls→6 BMarks, 60 Souls→12 BMarks). Imagine asking someone to spend 25 burning marks just to get 3 burning marks back… Now imagine the Epic chest system getting more and more Immortals every season (at some point the Immortal you want may not show up in a season), and more and more Level 30 seasonal Immortals (because shame on the people that support the game, right?) to take up space in the drop pool for Epic Chest refunds.
I really wish they’d do something about it, but I doubt there’s enough Epic Chest users to get this kind of logical problem noticed.