I would argue that Kaalia is the most-played leader of all time, at least from where I'm sitting
Here are a couple: Cyan: Vengeful Samurai is not an easy card to get out given his high cost of 7 Mana, but this can easily be brought down as this number is decreased by one for every creature in the Graveyard
I was ready to dismiss him as just a boring humanoid monster, but this little detail makes him feel a bit more flavourful
Halana and Alena, Partners is the strongest Gruul gold card in the format, and with direct support from the modified themes in Neon Dynasty , it looks to be where the color pair will be headed for the rest of 2022 as well
There is the FFVI deck starring Terra , FFVII starring Cloud, FFX starring Tidus , and FFXIV starring Yshtola