Basically the title. In 1994, the Rwandan genocide scattered the historically powerful Tutsi in favor of the more populous Hutu people. Yet in 1997 in the First Congo War, Rwanda lent support due to its Tutsi dominated government(still new to the subject, correct me if I’m wrong). How is that even possible? Wouldn’t any Tutsi want to steer veryyyy clear of Rwanda after that? How were the Hutu who perpetrated such a genocide lose the reins of power to the very people they targeted in just three years?
Your question is implicitly answered in the excellent comment of /u/Commustar on the Rwandan genocide
You should read the entire comment for context, but this is the relevant provision to your inquiry:
"So, as the genocide is happening, the [Rwandan Patriotic Front - a group of Tutsi exiles] is not idle. Paul Kagame, the head of the RPF, warns in April that they will begin fighting again if killings of Tutsi civilians do not stop. The RPF quickly began an offensive in mid-April that swept through eastern Rwanda, and surrounded the capital Kigali. Further offensives drove into the center and west of the country, forcing the Rwandan government, armed forces, and interahamwe militia to retreat towards the border with Zaire (now DRC), and eventually to cross the border into exile in Zaire.
So, what happened next?
The RPF captured the capital in August and declared themselves to be the new government of Rwanda."