Complex sentence: What Haruhi does not know is that she has an outstanding power to change the environment around her as she pleases, and by subconsciously using it she gathers Mikuru Asahina, Itsuki Koizumi, and Yuki Nagato into one place, the SOS Brigade.
Split into simpler sentences: What Haruhi does not know is that she has an outstanding power to change the environment around her as she pleases. By subconsciously using it, she gathers Mikuru Asahina, Itsuki Koizumi, and Yuki Nagato into one place: the SOS Brigade.