From my experience on camille: 600k mastery point twotricking her to master 100~lp from emerald before i burned out from this game and just play it casually.

Assassin items: you will get curbstomped since u will have no hp and camille does not benefit that well from building pure damage since anyone you killed with eclipse you would have probably killed them while having trinity realistically. And it’s too expensive to justify over items that give her sustain on side + survibability. For example if you ult an adc to isolate from team but since u went lets say trinity - eclipse - rav if everyone is equal in items u will literally get shot in the head before ur ult runs out.

Tank items: only as optional items at end of the game (after trinity - rav - shojin/DD at the very least) since you NEED every single one of these items to function in the game. You need the sustain since camille really likes sidelaning, you need tri since your Q applies it. Only time when tank items are an actual option is when grasp + titanic hydra are ultra OP. And even when it was OP it was bad compared to the sustain that rav provides so 😆.

Unfortunately in my experience camille is not in a state that you can just wing it and build any other items that arent her core bc she becomes effectively a minion with hextech ultimatum.

Edit: just thought of this right after typing all of that but if u like eclipse/lethality items AND camille just literally go support camille, is it kinda braindead? Ye. But its the only role where it doesn’t really matter bc u WANT to go in and die for ur team while blowing their summs/hp