the last boy on earth( male assasin creed reader x massive crossover harem)

what if a virus kill almost 99.99% of the boys and only the 1% who survive? that boy was Y/n L/n was giving birth before His mother die, he was the only boy on earth along alot of girls( from normal to Shinobi,superpowers,servants,Yanderes,angels,demons etc) however was taught the arts of assasin by a simulación of Each assasin of different ancestors from Altair to Ezio to Edward until the Egypt assasin.

can one boy survive this crazy earth fill with girls? what could go wrong.....alot