D&D General Eberron: recommend an edition

[Voadam]

While that is a tone explicitly gone for in the 3.5 core book and executed in some of the supplements with lots of low level important NPCs (The Lord of Blades is a CR 12) there are high CR stuff throughout the setting.

I just looked up the Lord of Blades in the 4e Eberron Campaign Setting and he jumped up to a level 21 elite monster. Elites count as two regular monsters of that level.

4e goes up to epic level 30, but the lord of blades is an appropriate top tier mid high teens end boss fight.