Sona and a mild rework idea

So had a conversation with someone and we got to talking about Sona's aura's and how strong/weak they feel. This lead to an idea of what if her Auras functioned a bit differently. We came up with the idea that the aura's should provide a tier'd buff per ally tagged. At tier 1 their is no bonus, this prevents Sona from having some insane power level if she ever manages to go Mid lane as a mage. Tier 2 gives a small buff to the champion(s) effected.

Maybe for her Q its a little extra bonus damage, nothing big but enough that tagging an ally is worth it. Tier 3 maybe provides vision for 2 seconds, something that provides a way to prevent champions from popping into bush for total safety. Don't know what tier 4 would be, but was thinking tier 5 could be a 1-1.5 second stun.

Could make her W do something like shield at tier 2; damage taken reduction at tier 3; heal off next auto attack/ability at tier 4; and ignore first attack at tier 5.

E could wipe a slow at tier 2, tier 3 could give the champion a 20-30% slow on their next attack; teir 4 ????; Tier 5 allows champion(s) to be immune to crowd control for duration.

The thing to "balance" this would be that that bonus would apply in the order you tagged your allies, with Sona always counting as first champion buffed. So if you position badly you might end up giving your combo mage the stun ability but they can't use it because they are to far back in the group to auto attack (or are to close to death to risk getting into range).

To make it a little more interesting i was also thinking about the idea of the buffs stacking BUT only if you tag players at the same time (basically upon activating the spell, instead of running around tagging your allies). This would give a HUGE skill ceiling for Sona where you have to know where you are, where your allies are, where they are likely to go, and how to position so you get the max benefit of each of your auras and don't waste a good bonus on a champion that doesn't need it.

This is a really rough idea, but would love thoughts on a change to Sona where instead of flat bonuses with low individual AP ratios, but insanely high over all ratios (assuming full team tagged), you get a champion that functions mildly differently the more allies they help with each spell.