[FaeLenx]

Your math is kinda awful there for its worth in momentum in a team fight. You could kinda say that about anything. The difference with shine knighting in a larger team fight is actually to its benefit. A defensive skill scales to the amount of enemies fighting/damaging you in value whereas an offensive skill does not usually do so unless it's an AoE. So yes, the transformation is worth roughly 36 momentum in that scenario. And I do mean worth. It's weird that you'd bring up team fights for shine knighting when that's one of the scenarios where it's actually really good.

The weapon itself is fine. In regards to scaling, it's normal. It also offers stats, and it's a sword so you get all of the opportunities that offers.

But it's, in the end, a handslot item that offers 2 full immunities. It doesn't need to offer those immunities to still be good. Most people you fight, as you pointed out, will not be negatively impacted by those immunities and it will still be a good invocation. Nerfing those immunities will be a tiny hit to its overall goodness while a massive hit to its meme potential as a handslot item that people will slot in to turn other peoples' builds into meme builds by making them so easily negated by an item.