I play Anivia for a while now and I am still not sure if my item order is good (at least its not total fail imo) or if there is some awesome item I have overlooked.

So it would be nice if you pros could look over it and give some tips.

Start: Sapphire, mana pot, hp pot
- Cataclyst
- Boots 1
- Meki (depending on income could be after RoA)
- Road of Ages
- Boots as required (Mostly Sorc when the enemy starts using magic resist. Mercury or ninja is also possible depending on situation)
- Chalice

After that its heavily game dependant.
Choices are:
Abyssal Scepter
Void Staff (especially when I not got sorc boots)
Zhonyas Ring

Archangels staff would likely be better than the Chalice, but so far I don't have enough income to finish the item before the game is pretty much already decided. It also leaves me with not much mana regen till I at least have the tear.

I toyed with getting archangels instead of Roa (starting with tear), but imo that leaves me too squishy and RoA has a better payoff until late game.

Is there something I a missing or should I change something? Also, nothing is set in stone. When I play against Siv and Cho and need mobility boots come earler, sometimes before finishing RoA, etc.

I feel that this build lacks AP and thus doesn't make full use of her burst capabilities.

The chalice is there so I don't have to go back after every team fight and can support pushing. With Anivias required huge mana pool you imo need some form of mana regen and chalice seems to be the best regen/cost you can get.
But you are probably right and instead of the chalice I should get a tear.

I still have to get my head around buying the same end tier item multiple times. But as RoA needs time to charge, wouldn't an archangel staff not be better? That way I could save the chalice. It only takes a bit longer to buy...

How does Guardian Angel interact with rebirth exactly?

If Guardian Angel and Rebirth are both ready, the Guardian Angel will activate first upon death.

I would actually suggest Haunting Guise as a replacement for Chalice. It doesnt offer the extra mana that Tear does, but it does have better regen, as well as CD reduction and magic pen.