@Jpwong well, if that is the case then modern and stronger alloys would most definitely win. However, we do have to consider the fact that the setting of the series is in a different era so the resources are also not as advanced.
In such a case the ranking in weapons would go Mythril ,Damascus steel, steel, Iron, Orichalcum, Common Bronze. Now, if they really wanted to make Orichalcum "legendary", they could compensate for the lack of density with high affinity with magic and enchant stacking and make mythril highly magic resistand and also incompatible with most enchants. There are ways to make a metal with low density "legendary" in an isekai. you just need to think outside the box a little
But yeah, a modern Damascus sword would probably lose to more advanced metal...however, I think it would be perfect for specific thin blades like katanas or even rapiers. It would make them quite resilient and last through many hardships and clashes. I have a suspicion that even the authentic Damascus steel had properties of superplasticity which allowed it to fold more and better than common steel. in today's era, there's been an experiment where they set up a katana and strike the edge with a rifle. it cuts about 3-4 bullets in half before it starts getting chipped away.
I believe that the authentic Damascus steel would last longer