So I went SOSing today. I set out for shiny Magikarp or Gyarados, but the Magikarp struggled to death. ;-;
Then I set out for a shiny Dhelmise. When I went fishing at the only spot you can find it, I encountered a Wailmer. It was at a low enough level that it wouldn't slaughter my SOS team. So I was like sure, let's get that shiny purple thanos whale.

I got a shiny
T H A N O S

(TerryCrews is a Buzzwole if you wanted to know)

And after only this many encounters:

I'm not kidding.
The odds of finding a shiny at this stage of an SOS chain with the shiny charm is 3/4096. (It also has no chance of getting a hidden ability, and has only one guaranteed perfect IV, but that's not what I was hunting for.)

An accurate representation of me:

(I always freak out when I find shinies)
Nature reveal:

It actually wouldn't do too bad competitively, if I were to use it competitively. Which I'm not.
Its one guaranteed perfect IV is in speed, rip. On a plus side, its defense IV is almost perfect.