How do enemy levels scale in the Arena?

I just set a personal record 48-win streak in the arena, and the creatures at the end were WAY harder than realm level 48. How does the scaling work in the Arena? Is there some proportion between arena level and realm level, or are they both exponential with different bases, or…?

It scales exponentially but at a much faster rate than realms do.

While I can’t give any exact numbers, creatures at around fight #300 have just about the same stats as the creatures around realm lvl 1200 with the same team (So same levels).