How To Forge A Magic Weapon (for a zealous vendetta)

Follow the normal costs etc for magic item creation in whatever system you’re using, but tack this on for a dramatic scene? Use it however you want, I don’t know.
You will need to track down METAL, FUEL and a liquid for the TEMPER - there is probably some quest you can do to obtain each of them
It is a difficult task as well, so you will need mental DISCIPLINE and physical EFFORT

Ripped from Moby Dick

METAL

You need something to forge. If you are on a quest your GM should probably come up with something metallic that is significant to the target.
Examples:
1 - gold from the crown to kill the usurper
2 - green metal from the meteorite to take down the alien ubermensch
3 - cursed bronze from a sarcophagus
4 - beating iron from a golem’s heart
5 - ancient helm of the vampire slayer to kill him again
6 - the gathered nail-stubbs of race horses

For dramatic purposes you should intone the history or context of the metal as you bring it to the forge, and maybe make an oath on it or something. Then it is time to test DISCIPLINE.
Smithing is a difficult task both in mind and body. DISCIPLINE is a mental stat (INT, WIS, or CHA) that you now test as part of the planning process. Pick one, and describe why it is apt to the task - imagining the desired form or considering the logistics, etc. This should be a roll under test, or if you are a roll-high kind of fellow it’s a DC 15. On a success you proceed as usual, but failure increases your chances of failure later but it will come back to haunt you.

FUEL

While you actually need to make a fire before anything else this seems like a good spot, dramatically. But anyway you need something to burn (usually it’s coal or charcoal because it’s hard to get sufficient heat from other materials but this is a fantasy game and something with dramatic and mythic significance burns hotter than any coal. This isn’t mentioned in Moby Dick but is nevertheless an important step).

Examples:
1 - Heartwood of a grandfather treant
2 - Staff of the archmage/druid
3 - Stuffed doll possessed by restless dead
4 - Anthracite from Khazad Dum
5 - Splinters of the wreck of your old ship
6 - Melted bones of murderers

As the fires get hot you should most certainly say “by the fires of the burning eye of Los” or what have you. The metal can now be worked and it is time to weld and shape the pieces. This tests EFFORT.

This is a physical stat (STR, DEX, CON) and you can pick one you are good at but must describe why it is an appropriate choice - why you need to be strong, quick, or gritty as you hammer the metal or work it in the forge. Test in the same way as DISCIPLINE, but instead you roll under half/ the DC is 20. If you failed the first test, roll twice now and take the worse result.

>Failure here means you messed it up enough that you either start over and pay half the cost again or you have a totally mundane version of the weapon or you have your magic weapon with some suitable drawback (basically a cursed item).

If you are happy with what you got it needs to be heated once more and given a final quenching. For this you need some liquid.

TEMPER

Examples:
1 - Viscera of a mythic beast
2 - Meltwater from the holy mountain
3 - Wine of the Elf nobles
4 - Gel from a living ooze
5 - Sewage from a Hill Giant steading
6 - Blood of three pagans
It would be good to prepare some sort of blessing or curse (in Latin if possible, with explicitly dark content to show your growing monomania with vengeance) and you can give it a cool name now if you wish.
After that, all that’s left is to kill the whale.