Ashe Major She can set up picks on you easily and often. Consider building Boots of Swiftness and/or Mikael's.

Alistar Major Your silence is pretty useless against Ali ever since they updated his combo. Abuse his weak level one, push for level two first, then play passively.

Aphelios Even All you need to look out for with Aphelios is his Gravitum (purple gun that roots). When he has it up, respect him.

Bard Extreme Bard out-trades you in lane and roams much better than Soraka. Your mid laner and jungler are not happy. Start Relic Shield and take a Guardian rune page.

Blitzcrank Extreme Big kill threat in lane and good roams. Do not pick Soraka into Blitzcrank.

Brand Minor You out sustain his poke easily. Take Second Wind and an MR rune. Start Relic Shield.

Braum Tiny Poke him out. One of Soraka's best matchups (as long as Braum isn't paired with Lucian, then it'll be rough). You could start Spellthiefs or Relic Shield, depending on who the ADCs are.

Caitlyn Major Cait's autoattack range and net make it really difficult to land Starcall or even auto her. Start Relic Shield.

Camille Extreme She can easily dive you. Over and over... build Zhonya's and hope for the best.

Draven Even You can Q where his axes will land. Draven is still very strong in lane, so respect his damage (especially if he's paired with an aggressive support). Start Relic Shield.

Dr. Mundo Tiny All tanks/immobile juggernauts are free Starcalls in skirmishes and later game fights.

Ezreal Minor A little hard to land Qs on him, but his shift is a long enough CD for him not to shift every Q you shoot. Ezreals tend to play very passive in lane which is good for Soraka. Start Relic Shield.

Fizz Extreme Big dive threat. Consider buying a Zhonya's for his fish.

Janna Tiny You out sustain Janna easily, and can cancel her R with your Equinox.

Jarvan IV Major Dive threat, but not a big enough threat by himself to justify buying Zhonya's.

Jinx Minor Jinx can only be scary with a heavy engage support and if your ADC is weak early. Otherwise, you shouldn't lose lane 2v2 against Jinx.

Jhin Major Respect his pick potential.

Kai'Sa Minor Only worrysome if you get cc'd and allow Kaisa to ult behind your backline and kill you. Kai'Sa is fairly short-ranged so you can harass her early if your 2v2 matchup is favourable. You could start Spellthiefs or Relic Shield, depending on who your ADC is and who Kai'Sa's support is.

Kalista Extreme Strong early lane, easily dodges your Q, scary pick potential with her R/E slow. Start Relic Shield.

Karma Major Karma has a stronger lane and late game, Soraka has a stronger mid. Start Relic Shield. Avoid picking Soraka into Karma.

Kog'Maw Tiny No pick potential, weak lane.

Leona Extreme Consider dodging in champ select. Soraka will get ran over from levels 1-18. Start Relic Shield and take a Guardian rune page.

Lucian Major He can dodge your Qs easily and has one of the best lane phases for an ADC. Respect his early damage, push for level two.

Lulu Minor Out sustain her poke her lane. Lulu will start to outscale you at around 2 items.

Lux Even She has okay pick potential, but it's a skill matchup. If you dodge her bindings, you should win lane. Start Relic Shield. Consider buying a Mikael's.

Maokai Tiny All tanks/immobile juggernauts are free Starcalls in skirmishes and later game fights. Consider buying a Crucible for his W/R.

Miss Fortune Minor MF only has one slow and no other CC. She's really only scary when paired with Leona/Nautilus/J4. Save your Equinox to cancel MF's ult.

Nautilus Extreme Consider dodging in champ select. Soraka will get ran over from levels 1-18. Start Relic Shield and take a Guardian rune page. Crucible isn't very useful against Nautilus, either. You can Crucible Depth Charge's stun, but not the knockup (The knockup lasts for a flat 1 second, the stun lasts for 1/1.5/2 seconds based on rank).

Nasus Minor Build a Crucible or QSS if he keeps withering you. Note that Crucible will remove the slow, but [i][not[/i] the attack speed slow. It might be more worthwhile for your ADC to build their own QSS to use on Wither. All tanks/immobile juggernauts are free Starcalls in skirmishes and later game fights.

Karthus Minor You can R his R. Consider buying a Locket.

Kennen Major Dive threat. Consider buying a Locket.

Ornn Tiny All tanks/immobile juggernauts are free Starcalls in skirmishes and later game fights. Also, save your E to place it under him before he goes to R2. You can cancel Ornn's ult every time, easily.

Poppy Tiny All tanks/immobile juggernauts are free Starcalls in skirmishes and later game fights. Consider buying a Crucible to use on whoever Poppy stuns into a wall.

Rammus Tiny You can cancel his Q with your E. All tanks/immobile juggernauts are free Starcalls in skirmishes and later game fights. Consider buying a Crucible for Rammus's taunt.

Sion Tiny Cancel his Q channel with your E. All tanks/immobile juggernauts are free Starcalls in skirmishes and later game fights. You can use Crucible on whoever gets hit with a charged Sion Q to cleanse the stun, but you can't cleanse the knock up portion. The knock up lasts 0.5 − 1 (based on channel time) seconds and the stun lasts for 1.25 − 2.25 (based on channel time).

Shen Tiny All tanks/immobile juggernauts are free Starcalls in skirmishes and later game fights. You could consider buying a Crucible for Shen's taunt.

Yasuo Major His windwall blocks your Q, and he's a major dive threat if the enemy team has an AoE knockup like Gragas, Orianna, or Malphite ults.