Sanzu is the trigger. Glad it was confirmed.
Good chapter.
But yeah no matter how hard Shin tries, and he tried really hard
Mikey is simply cursed.
That is Shin is cursed by having his desire twisted and doomed to fail. Most definitely the old man's curse
Speaking of the old man he was probably cursed too. That's why he's a disheveled hobo living under a bridge even though he has the power to travel through time. It must be that those who acquire this power violently, in other words by killing those in front of them who had it are doomed to fail and are cursed. That's why imo Takemitchy is successful and will save Mikey. He already achieved his primary goal of saving Hinata and will most likely be able to save Mikey as well. As far as we know Mitchy never killed anyone to get his time leaping power.