[2024] Finally completed the MOST DIFFICULT ACHIEVEMENT on Hearthstone! After exactly 35'630 Arena Wins on EU server, I finally made it!! | Flawless Azeroth Gladiator requires to Finish Arena runs 12-0 with all 11 classes.

Incredibly impressive. Just checked the data, and this is indeed still the rarest achievement, with only 13 people having completed it. Cheers!