Unknown Grail War

A new Grail war suddenly starts. This one having no build up for it and randomly starting. After the clock tower realises this, and find out that it’s the greater grail, they send out some magus to find the masters for their team. They do. But unlucky for them, their team consists of a bunch of non magus humans who have to cram everything they have into one study session before having to summon their servants as the other team did as well. While the other team is a team of elite magi who seek the destruction of the clock tower, magus life in general or the ability to do as they wish at their own leisure. Which team will win? The underdogs that nobody expects to win? Or the team of elites who only wish for death and destruction?