User blog comment:Emptylord/Season 3 - PBE Patch Notes/@comment-141.51.214.75-20121116122653

So, the changes to a fully charged Archangel's staff are... odd. You lose 400 mana (seraph gives 1k, archangel gives 1.4k) gain 3 AP (Seraph gives 60, Archangels gives 45, +12 for 400 mana = 57), you loose 15mp/5 (Seraph 10, archangel 25) and the 3% of your mana become ap passive becomes unique. However you gain the ability to shield yourself from damage.

Now, there also is the practice of stacking archangels on, say, Karthus. Let's see how the changes affect him:

The previous "perfect" build allowed for 4 Archangels + Rabadons + boots, resulting in 1035AP, 100mp/5 and ~3968 Mana (on Karthus)

4 Seraphs + Rabadons would result in 703AP, 40mp/5 and ~5368 Mana (again on Karthus), which allows you to shield yourself for ~1342 damage for 3 seconds if you get jumped out of nowhere while at full mana.

So, if you're just going to buy one archangle, like most people do, it's up to you wether the shield is worth 400 mana and 15mp/5. But if you get several archangels, I can't help but feel RIOT dropped the nerfhammer on it. Yes, a 1.3k shield is ridiculous, but 300 AP aren't exactly peanuts, either.

Unless you're playing Ryze. Stacking Seraphs actually looks like a viable course of action for him now, with the shield copeing for the lost resilence. I gotta try that.