I'll admit to being rather partial to swords. So, a long sword modeled after the blades of the Dúnedain with the qualities of Undead-bane and Foe-slaying.
I would also go for a sword. Its powers would be the ability to cut through anything and have its own pocket dimension where I can summon or dismiss it at will.
Hey, I created the perfect murder weapon! 😈
Okay, if I were to forge something, it would probably be some sort of dagger. It'd be able to change size, material and shape, to appear as something innocent, and change back at will, and it would also be able to glow (different colours) also at will.
you want an adjustable lightsabre
Pretty much, but I wouldn't want a Lightsaber because I'd accendently poke my leg and I wouldn't have a leg, whereas with a sword I'll just have a cut.
What I meant about the changing sizes and stuff is I could make it look like a pair of sunglasses, or a scrap of cloth to get through metal detectors or something.
Lightsabers are finicky weapons indeed.
I have a pretty strong personal sentiment for kama, a type of Japanese farm tool/weapon. They are excellent dueling weapons and can be made to work in larger fights, i.e. battlefields. They also require a frick ton of training to learn how to use. I'd forge a set of those, and if we're talking about enchantments, I'd go with personal agility and awareness to basically jump around like an elf.
Maybe you'd be interested in Asayama Ichiden-ryu Heiho. That style includes training with the kama. Of course, I doubt it's taught outside of Japan.
Here are a couple of short videos:
Hooold on, I didn't say I wanted to train with them... but you have my interest