hell naw, the 1st hero made over 100 kids to fight the demon race, damn

if MC did same, he’d probably dry up and die faster (1 wife = 100 kids, 3 wives = 300 kids). that’s basically building a whole army

and Ryushika, the virgin old elf vs Yuuri, the perverted saint.
The 1st Hero had over 100 kids from
multiple races, aka., he had multiple wives.
Since, aside from Humans and Demons, the King mentioned the names of 5 other races, aka., Elf, Dragonar, Dwarf, Beast & Mermaid
(for whatever reason, the translator for this series went to translate the Kanji's rather than the Furigana reading, which should have been the one translated).
So, the 1st Hero probably had multiple wives from all the 6 races (barring Demons).
Even if we consider that he only had atleast 1 wife from each race, then on average each wife had atleast 17 kids.
And the numbers would drop per wife, the more wives the 1st Hero had.
So, MC having 100+ kids technically isn't impossible, if he has more wives.
I mean, apparently there is a real life man named
Feodor Vassilyev who allegedly sired 87 children from his two wives.
Apparently his first wife (Valentina Vassilyev) gave birth to 69 children
(16 pairs of twins, 7 sets of triplets, and 4 sets of quadruplets) and his second wife gave birth to 18 children
(6 pairs of twins and 2 sets of triplets).