Items that upgrade themselves

[Alexander]

I have a snake ring, that could be upgraded. I tried to fight it to upgrade and it wiped me, so I figured I'd leave it alone. Somewhere along the line, I started using snakes and unbeknownst to me, it started gaining in morale until eventually it upgraded itself, saying it was 'pleased' with me. I can only assume it's because I was using snakes.

Are all upgradable items like this, they gain in morale by meeting certain conditions and upgrade themselves? And if so, is there any way, list or guide to find out what conditions improve what items?

Any help would be greatly appreciated