I'ma be real with you, the MC has taken every opportunity to show they're dumb. Taking risks at the start blitzkrieging a dungeon with possible traps,
having ZERO knowledge of using his abilities, AND not trying to learn about summoning as his first priority,
deciding his best strategy was to be CLOSE to the golem instead and making himself a target when getting away ASAP was much, much, much better so his summon doesn't need to divert focus defending him,
and then having zero questions on the magic-ritual here. Obviously blood is another fluid. Sure, he may not want to pick blood, but the sheer fact he has zero questions and just... accepts? it's semen? seems very stupid. I can handwave not using urine, since a waste product having low mana makes sense.
Whatever, I just hope MC pulls something decent in the future. Like growing a spine. Or a brain.