Otaku's Time Travel Story: from Comprehensive Comics to the Altar

"Ding! The strongest time-travel system has been loaded, and the host has entered the world of "Comprehensive Comics"." "Huh?! A comprehensive comic? What the hell! No... So where am I now?" "The host is currently located in "School Apocalypse"." "School Apocalypse?! Doesn't that mean the zombie wave is coming?! Wait a minute - I have no power, I can't even defeat an ant!" "Ding! Trigger mission: Survive for 24 hours, reward - 'Great Sage' skill!"