Because he has all the slayer cards, possibly even max leveled. This is what I was talking about with the paying players currently having an enormous advantage. I've even tried buying some event gacha, but all I got was the R card. Not nearly enough to get me caught up. My only chance is to get both the SR cards. Until then, I'm slowly falling more and more behind.
I was at rank 98 after the first day, and now I'm pushed back to almost rank 350.