I'm gonna be honest, I like this mechanic. It breaks away from wild pokemon encounters where it's like the wild pokemon's going "Heeey, I wanna play!" and "Aww, you have no more pokemon? Okay buhbye!" to the fact that the wild pokemon would be gunning for you, directly, instead of waiting for you to send out a pokemon, and if your team gets laid out, it doesn't let you get to a safe haven, it tries to remove you from this mortal coil.

Luxray: