Uno

One is a light blue Arabic numeral 1. One's color is similar to that of Four's, albeit slightly paler. She is armless, unlike the other algebralians. On some occasions, One’s eyes appear slimmer and more tilted.

One likes to “help people out”, such as when she gave Fanny a new mouth and gave Ice Cube new legs. However, her full intentions are still unknown, but it’s suggested that she wants to get ahold of Two’s Power some way or another; saying she has power, just not enough. Her deals consist of offering various contestants things they desire, in return of them doing a “favor” for her later on. This may imply a more manipulative and sinister side, thus supporting the speculation of her being an antagonist for TPOT.

During "Category One", she shows her more malicious traits, such as blackmailing Basketball into making a deal with the threat of making Robot Flower (while programmed with Flower's Season 1 personality) even more destructive. This, as well as the storm in general, shows her complete callousness and pragmatism, not caring about the well being of any affected and remarking on her boredom while Basketball made her decision. In addition, the way she kept Basketball and the eliminated contestants she kidnapped may imply that she is forcing her victims to make deals with her.

During "Seasonal Shift" her true power and malevolence is shown as she helps trigger the ripping of the entire BFDI reality just to make Gaty sign her deal. Once she does, she effortlessly fixes most of the damage done. This shows how her want for Two's power (allegedly) is more important than the lives of the rest of the inhabitants of the BFDI universe.

It's alleged that the deals One makes with the contestants consist of if the contestants that signed the deal wins The Power of Two, all power is given to her. This is supported by the fact that, like previously stated, she wants Two’s Power all for herself.