How to make Soraka Healthier
We want to hit 3 points with Soraka:
1. Make her more interactive in lane and prevent AFK I heal behind my ADC play style.
2. Move power from early/midgame to lategame so that she is less oppressive when she gets a lead.
3. Allow ways to play around GW so that Soraka can fulfill the healer fantasy in late game
Q changes - - - - Rejuvenation is a neat mechanic for Soraka to sustain her health. That is often all it gets used for and it rarely matters when in teamfights as damage stacks too quickly for the duration to hit. I think Q should drop this mechanic for a new one. A simpler one.
Astral Healing: Healing done to champions below 40% health are healed for 10/20/30/40/50% more health from healing effects from Soraka's abilities.
Sweet simple and feeds into the healer fantasy. I want to note this would affect Soraka's self-heal too but it does not work with items like Redemption or Athenes. I don't think Q needs any changes other then this but this does leave Soraka with a self sustain problem but it will prevent long range Q self-sustain that makes it so she doesn't need to interact with enemies. This also has some overlap with her R which I will get to later. Putting "healing effects from Soraka's abilities" into the text prevents the extra healing from going onto items like Redemption or Athenes.
Passive Changes - - - - With the above changes to Q this leaves a good opportunity for Soraka to gain a meaningful Passive.
Salvation: Abilities Damaging Enemy champions will mark them with a stack of Salvation for 7 seconds. When Soraka attacks an enemy with an auto attack that has a stack of Salvation it will reduce their damage by 7/14/21% (1/7/14) for 2 seconds and heals Soraka for 20 + 10 per level +20% AP over 2 seconds.
A strong self healing passive that allows Soraka to be a bit more aggressive in lane and requires her to engage her enemies if she wants to sustain herself and prevent her from just being a healing robot. This also has the effect of giving her more to do beyond just healing as she needs to weave her auto attacks in and can reduce the enemies damage as she does so. On a side note, thematically she is saving her enemies with this passive. Granting Salvation to the heathens making them question their choices (reducing their damage) and giving her time to heal.
W Changes - - - - This should change in value to balance out the Q buffs to her overall healing. 80/105/130/155/180 +(40% AP) should be the base values. The CD and costs should be the same. Soraka being required to get up and auto-attack to self-heal is a big change for her and she should still be able to heal a lot when the big fights break out. This ability (to me) is her identity and it should remain on a CD that scales down to a very low CD. With it being harder to sustain (you can't just throw out a max range Q to heal up) she will need to be more careful in when and how she heals. She needs to be an intelligent healer and not just blindly healing every little boo-boo.
Q changes can reward her a lot but she has to max it to get that effect. The combination of a maxed Q and maxed W is where her late game scaling comes into play. She really needs these both maxed to hit that high end healer in the end game as when they are both maxed the values are higher (270+60% AP) healed when both maxed) but they are lower until both maxed and that extra healing only triggers when they are under 40% health. I do note that the values are pretty close to what Soraka heals now but keep in mind she loses the ability to grant rejuvenation to allies losing some of her healing and the greater value can only be applied after they are below 40% health allowing items like Mello, and Exe to have already applied GW.
E Changes - - - - none.
R Changes - - - - 200/300/400 (I like round numbers, in all likelihood this is unneeded could jsut as easily be 100/200/300) and a small area around Soraka purifies allies preventing GW from reducing heals while they are within the area (1/2 range of W? A pretty small area to require more risk for greater heal). The area would last 1/2/3 seconds (maybe longer with all the GW options these days). R Loses the +50% healing at below 40% health. That was moves to Q.
The goal here is to allow Soraka players quick windows to play around GW as it is very easy for players to apply this these days. The fact that there will soon be a tank item doing the same and all role will have a way to shutdown soraka's fantasy. A small area around soraka, about the size of the Zeke's AoE effect would be perfect as it requires soraka to play in a dangerous area to heal more allowing players to target her if she tries. Removing GW is a dangerous thing to add to Soraka's kit so it needs to put her in danger and shouldn't be applied easily or for long. The small AoE that doesn't remove GW but prevents it from reducing healing is the trick. To be clear GW is still applied but while Soraka keeps her ally inside her Aura she heals for full amount. This keeps her in a dangerous area if she wants that greater heal and it's gated with a long CD.