The night was windy and shadows were all over the building that Tsukuyomi was inside doing his homeowkr. And he said "It's time to be the hero I have trained to be." lightning struck.
The next day everyone was in the lounge having fun and smiling and he came in and glared until everyone stopped because he hates smiles. He stood up and glared at his homework as shadows came out from his heart and wrote all the answers.
The next day, Tsukuyomi donned his hero outfit and became the shadow hero: Sentinel! He flew around the city to patrol, until he met with a new villain! "Idiot villain, you are not as smart as I" said Sentinel, but it was not enough.
"Behold! It is me! I am Murderus the murderous! I will murder you now!" and he shot a murder beam out of his heart and destroyed the nearby building. People screamed and called for help, so Sentinel killed Murderus and went to save the civilians.
"Help me hero!" they cried out, stuck under the rubble, but he scowled at them and said "The fool who cannot save themselves is a fool who is not worth saving."
And then the civilian died. Sentinel flew back to UA to report his success.
"Good work sentinel, you are a hero almost as edgy as me!" Said Ghost with a nod. Sentinel nodded back without a word and went back to the lounge to glare at all the students. When he arrived they were happily chatting and playing video games together. He strutted to the other side of the room to his corner and glared.
"Be silent, mortals. You are interrupting my brooding time."
The sun fell from the sky and night returned, a reminder to the world that good things will always end.
And so another day passed for Tsukuyomi.