Equinox embodies the dual nature of light and dark. Where one exists, the other must fade to the background. Her kit fully embodies this, with a form change ability serving as the heart of her ability kit. Her first ability will morph her from her light form to her dark form, and vice versa. Depending on what form you are currently in, your other abilities will change functions entirely. This reads as extremely complicated, but I assure you its not as it seems. The way it plays out in gameplay is you choose one of the forms, and just stay in that form permanently. This allows you to cater your build to excel in either light or dark, rather than being middling in both light and dark. Equinox is a support warframe, offering strong damage buffs that apply to herself and the rest of your team, as well as offering strong debuffs to weaken enemies. Notably, equinox is by far the most difficult frame to farm in the game due to her blueprint requiring both light and dark parts. For this reason, it makes her hard to recommend to a new player. However, if the themes of light and dark interest you, feel free to pursue equinox.