The issue with the Holy Avenger is that your kind of pushing the Paladin back to being a "Holy" warrior and 5E has removed that concept. Okay that is not really fair. 5E is designed to work with any game world but the concept of the Paladin can be adapted within the confine of it's rules to fit different options. For the Forgotten Realms, by lore the Paladin was aligned with a specific God or church. Under the 5E rules this is easy to implement however Larian decided to ignore this part of the lore.
