Tamers

A Tamer is a term given to those humans who are able to bond with a Digimon, thus creating a Digivice in the process. Tamers are also commonly referred to as Digi-Destined because their fates are usually bound to the Digital World.

Ultimate Tamer
Ultimate Tamers are the very first digs-destined to be in the Digital World, and the very people specially selected by Barbamon to develop a strong bond with selected digimons to bring about revolt against civilized groups. The plan turned to be a failure when the said tamer's resolve has exceeded Barbamon's control.

Ultimate Tamers, unlike a normal tamer during Digimon World Alpha, were selected due to their resentments to civilized life, which has strong foundations based on experience. Their growth and resolve, even their particular ideology at a time plays an especially strong role in their only partner's development, such as what digivolution their partner obtains and their special abilities.

Each of the Ultimate Tamer's digivice has a unique ability that varies from individual, and they may also carry passive abilities in the face of battle and can give them certain benefits over opponents.

Tamer
After sealing of Barbamon, the Tamers came in droves to the Digital World. As a way to ensure their existence and be an able power themselves, the new arrivals would quickly be paired with digimon(s). They're chosen due to them answering to the Digital World's call when it's troubled.