Its not just kill 20ppl I think.
In my noob days I went to pvp everyday, to claim gems and xp (like 500-600 gems daily if you go down to bout 8gems per kill, ez gems for me at that time), I killed so many players and I got it when my acc was like 4 month old (didnt went much pvp anymore, but sometimes), and well I’m still not sure how I got it, I just killed a player and got it.
Info says ‘‘own a random player in battlefield’’, but tbh I’m not sure what that should mean.