Stella stepped out into the light. The tunnels were hers, and it had actually been quite a boring process to take the last of them. Twilight had left a while before, making the final stretch of the exploration feel more like a chore that Stella had gone through with only because it was sure to be short. She scanned around, looking for Twilight, and found her staring at the distance. The Sun was a fair bit lower than when they'd begun to fight outside the castle in Ponyville. "Are you done wasting my time?" Stella asked.
Twilight was quiet. She turned slowly and deliberately. Her horn was alight, and her eyes were closed. Stella braced herself in preparation for what was to come. Twilight spread her wings wide and opened her eyes, and let her magic flow loose.
It did not head towards Stella. It did not head towards any direction in particular. It spread, filling the air around Twilight like a drop of ink spreading out through water. It reached and reverberated and weaved itself through the fabric of reality, and it twisted space as it passed through it like light through a lens.
The world bent around Twilight, and around Stella, and in the space between them. Twisted and curved and warped, stretched and shaped into something else entirely. The few metres of distance between the two mares became kilometres of space, the world around them suddenly unreachable, the spatial construct they found themselves in unbound by gravity and sunlight and any external factors yet still confined to that tiny space over which they had been standing. It was like watching reality through funhouse mirrors, like a demented mind's imperfect recalling of existence.
Stella soared through boundless spaces imprisoned in finite lengths by impossible shapes, flying to reach her destination on the other edge of their tiny infinity as all her spells and bolts passed around their target without ever touching it, like electricity sticking to the outside of a cage, like water obeying gravity over its own forward flow. Twilight seemed untouchable and unreachable, if only for a few moments.
Stella was relentless. She stopped firing spells she realised weren't working, and redoubled her efforts into moving towards Twilight, even while the very space around her fought against her motion and moved away with her inside. As she'd done in the tunnels she began to reach out with her powers, trying to bend reality around her in the same and opposite way Twilight was. She did not know the details and specifics of Twilight's spell and how she was using it, but she made up with sheer power what knowledge couldn't provide for. Slowly at first, surely all throughout, she carved herself a bubble of influence and first halted the negative course of her motion, then began to once more push herself through space at speeds beyond the definition of speed itself.
Twilight watched and perceived her, eyes glowing white, sweat running and evaporating down her back.