Michael's plot was nothing too complicated, but that did not mean that it was easy to pull off. After all, he was fighting a Fate God like himself. If not for the fact that Deeno had to split his attention thanks to Asteria's attacks, it would have been much more difficult for Michael to pull it off, and he would have most likely failed.
What Michael did was simply to nudge Fate and mess with Deeno's perception of it. As Deeno tried to use Fate to predict the attacks of his opponents, the false information that Michael had planted would be supplied to him instead, allowing him to make false predictions.
It was thanks to this that Michael had been able to breach Deeno's defense.
