Fun story that starts with the death of our old aged hero. He had a crippling Origin Card and never made it past the 10th level of the tower. When he dies it activates a Hidden Ability and returns him to just before he gained his origin card, a time when Humanity had only recently gotten to the 51st floor.
Spoilers below …
He’s now back in school, just before finals. His precious card’s bonuses are still in effect so he has perfect recall. He uses that to place in the top 10 of his year and complete all the achievements of the 1st floor. His new Origin Card is about Summoning and so he collects a few pets, pays off his outstanding loans, and kills some criminals.
He forms a party with 2 of his classmates and they set off to Ascend.
Final chapter does some world building and then shows all the current cards in his deck.