The Definitive Spheres Tier List

[SangoProduction]

Fair on the War sphere deal. Although I almost exclusively play it as me spending it to improve them, rather than having others worry about my stuff.
Just chime in with a "You can move 10 extra feet," or "+5 damage" when appropriate. Worst I've ever got was when someone was assuming that they did get the bonus movement, and I had to tell them that I was out of momentum.

As far as Mind is concerned... yes, you need a backup plan (if you don't have the Ignore Immunity advanced talent). And one talent in Destruction sphere has you settled. Destruction sphere just negates that downside. It fulfils its fantasy very well.

As for Conjuration. That's actually what I *don't* like about Conjuration. It's way too easy to be "good enough." Summons are very "visible" as an effect to the table. Summoning a locksmith is going to be more noticed than casting Knock, despite the former being strictly worse in most cases. (More ridiculously, you can get like 5 magical summons for 1 talent (and drawbacks) that can each cast life sphere. Which notably feels a lot more abusive than just being really good at life sphere.)
In my opinion, It also feels a very... mechanical... sphere. It's strictly there to do mechanics rather than fulfil some sort of fantasy.

And also fair on the Alteration point. I rated it C because I am literally never enthused to play an Alteration specialist, or even have particularly many talents. But it definitely deserves at least a B for the sheer fact that Transformation talent exists, which enables playing literally every creature in the game without homebrew (while even having it scaled down to your current level). And yes, it's got good utility.