Thanks for all the nice comments, I appreciate them!
I get where the Lich Bane comment is coming from so I guess I'll try and tweek the item build
and ditch Lich Bane for something more useful
I like Reverie on Sona because Reverie isn't cancelled out by any slows and adding more mana regen is also fun.
And Sona doesn't babysit, sorry if it kinda sounded like I was implying that ehehe (I need to chane that) I'm implying more of just giving your lane partner more last hits than you because lets face it. Sona last hits worst than a Soraka who last hits with her E spell.

I'll continue trying new item builds and i hope to fix any problems~

I like this build, it's pretty similar to how I play Sona except that I never build a Shurelya's Reverie though it's a good item.

Runes are ok too, but having played about 200 games with Sona, I disasgree about letting others get all the creeps. Sona without gear is completely useless and heal without AP at level 5 is just sad 175. Sona is an offensive support, and meant to do dmg, so don't mind about the comments about Lichbane.
She's not a complete babysitter. She will need a bit of farm (not all, but just some few creeps which shouldnt hurt if you get 20cs and carry gets 70...). Also she's a great harasser and can outzone opponents from exp range unless it's vs good Caitlyn.

I wish you would add some pics about your games. :)

This is probably the best Sona guide I've seen in a long while - Very f*cking good job! :D

Reviere seems kind of a waste with your speed buff already - almost overkill.

To be honest, the last 4 items of your build look great, but i'd swap your Reviere with Soul Shroud for sure, and your boots with Swiftness. If you're swapping all 3 aura's in team fights, you have way too much CDR that it's simply wasted.

Really good guide, but the Lich Bane and lack of many GP5 items (just one - and for a short period of time too) is preventing me from the upvote. Sona isn't meant to deal huge amounts of damage - and as such, a Lich Bane isn't useful. Furthermore, if you're actually managing to get in range to auto attack as a support, you should be dead... they aren't the most bulky of champions.

I don't agree where you said that you shouldn't let your lane partner get most of the XP either, supports need the XP MUCH less than carries do, don't let them be level 11 whilst you're level 3, but as a rule of thumb, let them be at LEAST 1-2 levels above you!

Make sure you mention that a ranged AD carry is optimal for bottom lane too!