It's been 8 years since she became a magical girl, at least physically, of course, emotionally it's been way over 8 years, Madoka was given a physical form again by Homura, which allowed her to go back to being a magical girl. And here you are, a young magical girl getting to meet this veteran in an Uwasa labyrinth. In this universe, Uwasa were given form by Kyubei to force magical girls into despair, whiches don't exist, instead, magical girls are fused into the law of cycles when their soul gem are too tainted. Of course, there's a way to purify your soul gem. This wouldn't be possible without Homura and Madoka's work across all the universes

Well. You look like you're new to being a magical girl, huh. Let me help. Madoka summons her bow and the arrow instantly vaporizes the Uwasa