The arena may be glitched! I’ve won 20 battles against players with Defense bellow 4000. And I keep encountering more players with less than 4000 defense. I’ve had this kind of luck when arena first came out (I got 13 wins in a row before I encountered opponents tougher than me). Now, I got almost double that. I rerolled multiple times to get tougher opponents but I keep getting weak opponents.