Rune Swords

Rune Sword
it is unclear if drops are the same as they are on rs but if so then the Kalphite guardian can drop it

it can be made with 89 smithing

Rune Longsword
this item can be bought at the champions guild

this item can also be made with 91 smithing

Rune Scimitar
again it is unclear if the fire giant drops the rune scimitar if so comment below and i will update

can be made with 90 smithing