Though Nexus embodied it, I feel like Agul was the one who truly brought in a sense of mystery to the series. His appearance, color and overall vibe was unlike anything the Showa Ultra Brothers, Tiga, Dyna and even his own partner Gaia brought to the table. And not to mention these soundtracks. They have a sense of unpredictability, which tbf kind of defined his character during the first half of Gaia's series.