Razen Blade

[DracoKnight]

Is this too overpowered? I know that it is to some extent, because you could effectively be dual-wielding greatswords - potentially in the form of a dagger.

Razen Blade
longsword, shortsword, scimitar, dagger; rare, requires attunement

This blade instead of dealing its normal damage die deals 2d6 of its damage type. This weapon also gets +1 to attack and damage rolls. With this weapon you also reroll all 1s, and you must keep the second result. This weapon retains any of the native properties of its non-magic cousins (i.e. a Razen Dagger would retain the finesse and thrown properties).

[Amnoriath]

Is this too overpowered? I know that it is to some extent, because you could effectively be dual-wielding greatswords - potentially in the form of a dagger.

Razen Blade
longsword, shortsword, scimitar, dagger; rare, requires attunement

This blade instead of dealing its normal damage die deals 2d6 of its damage type. This weapon also gets +1 to attack and damage rolls. With this weapon you also reroll all 1s, and you must keep the second result. This weapon retains any of the native properties of its non-magic cousins (i.e. a Razen Dagger would retain the finesse and thrown properties).

It really isn't. Dual Wielding only means you can make a consistent bonus action attack for 2/3 of your slots. Personally I would leave out the rerolls and put something more interesting flavor wise to leave GWS alone. Otherwise all it does is boost damage and occupies a slot.
P.S. You did though site an issue in that why would any one that would take this apply it to anything other than a dagger?

[bloodshed343]

Maybe deal 2d6 for one-handed weapons and 2d10 for two-handed.