The problem is that she won't really benefit much from the AP on Archangel's Staff. Only her Hymn of Valor and Crescendo benefit from AP (in terms of damage) and they don't give that much extra damage with only an Archangel's Staff and a Lichbane. Her Hymn of Valor doesn't even auto-lock on to champions until a relatively smaller range that it is quite unreliable as a nuke. Her Aria of Perseverance won't be improved that much more even with these two AP items because it only has a 25% AP scale. Song of Celerity doesn't even scale with AP. With just an Archangel's Staff though, Lichbane's extra damage won't be much better than Sheen's cause you don't have that much AP.

Manamune is viable, since she'll probably end up doing more damage via Power Chords and autoattacks. I think that getting just Manamune, Sheen, Banshee's Veil and Frozen Heart would be good, since it would give her lots of AD (from all the mana) and Sheen's proc every 2 seconds (no need to upgrade it, Trinity Force is too expensive and Lichbane does not actually benefit without any AP). You would also be very tanky and have a good -20% AS aura from Frozen Heart. The -20% CDR you get is very useful as well.

Regarding your choice of boots, I think Ionian Boots of Lucidity or Mercury Treads are better. The extra 20 Movement Speed from Boots of Swiftness is not really necessary for Sona given she is already very mobile with Song of Celerity. If you are getting Frozen Heart, that and the Ionian Boots of Lucidity puts you at -30% CDR which allows you to really spam, which you are expected to as Sona. Mercury Threads make Sona tankier magic-wise and grants her Tenacity, which is really useful on CC heavy teams, given Sona dies immediately if CCed.

I also think that Chalice of Harmony deserves a mention somewhere here. For players who have some mana problems, they can easily pick it up (it's relatively cheap). It gives another 30 MR which helps with your tankiness. It's unique passive also synergises well with Manamune and all the mana you might be getting for better sustain.

To afford Archangel's Staff and Lichbane, you really would need to farm as they are really expensive items. If the team needs you as a support, it would be impossible to get these while warding for your team as well, so you might want to think on that. Yes, I know Banshee's Veil and Frozen Heart are expensive items as well, but they help her more than Archangel's Staff and Lichbane does. These items might be affordable if she's mid? (which I think you meant her to be).

About the masteries, you need to update them. If you go deep into the defensive tree with the new masteries, you will get a really tanky Sona in combination with Banshee's Veil and Frozen Heart. You might also want the extra mana from the utility tree for more synergy with Manamune and Archangel's Staff.

Sorry if I might sound harsh, I'm just offering my thoughts on the build. The theory behind your items are sound, just that in practice, they are not as good as they may seem. Maybe if Sona had skills that actually scaled with AD (other than her autoattacks and Power Chords) and more skills scaling off AP (that are also reliable), hybrid Sona would be more viable.

EDIT: Alright, I tried the build already, so don't say I criticise without trying. The build is good in theory, but takes a really long time for it to be effective (that is, after your Manamune and Archangel's Staff is complete). I took AP mid role too and even then, Sona gets dominated easily (although she can play passively and outsustain), making it slightly harder to complete your build, which is quite expensive. The killing power only comes after the build is complete, so it is not too viable. Sona will still be extremely squishy and focused first because of it.

Also, starting with Meki Pendant + 2 Mana Potions give good mana sustain until you can get a Tear of the Goddess.

If you guys played Sona enough and learned how she worked you'd know this build looks killer. I haven't tried it but I'm excited too especially with the positive feedback.

Cool build. She actually does damage like hell.

Defense tree? Clarity? Boots 3? LOL this is just too much.

Thank you sneaky113 for trying it! Maybe share the score? Also the other 2, don't judge unless you've tried it. The clarity might seem like overkill but believe me its not.

wow this build actually worked :D

I agree with that. Anyhow the build is just weird, I don't see it work but then again I haven't tried it.

For info on coding just check the first link in my signature :)

Really? Manamune, Archangel's Staff AND Clarity?