NEET dakedo Hello Work ni Ittara Isekai ni Tsuretekareta - Ch. 42

[MangaDex]

 

[Opor97]

Hmmm 6 slow moving sturdy targets are slowly advancing....boy if only MC had some sort of big high damage area of effect attack like sommoning meteors...oh wait he DOES HAVE JUST THAT.
MC seems so incompetent, instead of solving the situation with his power he rather crys

 

[Xeroxcopy4free]

^ guy above me is stupid AF, it was already said that he has low mana and mana potion is no longer effective (though idk why they decide a mana potion lose effectiveness every time you drink).

 

[cksn]

shoddy dialogue in this arc, first angela before and now random elf's dialogue is literally like "hey you, i'm this kind of character - that's why, what i'm thinking right now is _____!"
looks so bad

 

[MarqFJA87]

^ guy above me is stupid AF, it was already said that he has low mana and mana potion is no longer effective (though idk why they decide a mana potion lose effectiveness every time you drink).

It was specified that it gets less efficient if you drink multiple potions in the same day; I assume that was just a simplified way of saying that the body needs either a relatively long time to fully metabolize an already ingested mana potion's mana-restoring aspect (which is probably nonphysical in nature and thus operates by different rules), or that said process only truly completes when the person falls asleep (just like how IRL the body's healing processes accelerate significantly during sleep).

Out of universe, there is a much more obvious answer: it's a drama-preserving handicap that prevents such potions from being abused to greatly reduce or completely negate the possibility of running out of mana to cast spells.