Why is Jhin's favorite number 4?
Idk if this is technically a game, but you can try it yourself.
Step 1: Take ANY number
3756
Step 2: spell it out
Three thousand seven hundred and fifty-six
Step 3: Count the letters
T-h-r-e-e(5) t-h-o-u-s-a-n-d(8) s-e-v-e-n(5) h-u-n-d-r-e-d(7) a-n-d(3) f-i-f-t-y-s-i-x(8) = 5+8+5+7+3+8 = 36
Take your new number and spell it out as in Step 2.
Count as in Step 3
Repeat
...
Until you end up with
4
F-O-U-R = 4