1. Runes

Essentially, all rune setups are based on Storm Surge - Shadowflame. If you're building a mana item as your first core, take Axiom Arcanist instead of Manaflow Band.

For builds that get high ability haste from items, like Blackfire Torch - Cosmic Drive or Seraph's Embrace - Cosmic Drive, you can take Axiom Arcanist + Scorch instead of Transcendence to give you more power in the early laning phase.

As for the rune shards, it's a matter of preference, but since the Storm Surge - Shadowflame build doesn't give you any ability haste from items until your second core, I've been taking the ability haste shard.

For flat health vs. scaling health: if you can dominate the lane before level 6, take scaling health; otherwise, take flat health. To be more precise, take scaling health against assassins, tanks, and short-ranged mages. In matchups where early wave priority is crucial (vs. Orianna, Xerath), take attack speed + flat health.

You don't have to follow the runes shown in the screenshots exactly. For secondary runes, you can also take Bone Plating + Overgrowth (against assassins or burst mages) From the Inspiration tree, Biscuit Delivery, Triple Tonic, and Cosmic Insight are also good secondary rune choices.

However, 1) If you're building a mana item as your first core, take Axiom instead of Manaflow Band. 2) If you take Electrocute, always take Cheap Shot + Ghost Poro. Let's stick to these two rules. If I had to give a hundred concessions, I'd say swapping Cheap Shot for Taste of Blood is acceptable. *Make sure to take Cheap Shot and Ghost Poro. Currently, Zombie Ward has the highest pick rate instead of Ghost Poro, and it's tanking the win rate. Let's take Ghost Poro and use wards frequently to stabilize the laning phase.

Electrocute is a rune that empowers kill threats and skirmishes rather than early laning poke/pressure. Since the buff, Electrocute can chunk the enemy's health a lot with just one proc thanks to its insane damage, but otherwise, it's a bit weaker in lane compared to the Arcane Comet build. (Though taking Scorch can help cover that.)

It's a rune you take to apply strong health pressure after Q evolution, sending the enemy back first and then joining fights earlier, or to use Electrocute's overwhelming damage value to quickly focus and eliminate one target in skirmishes. In this recent meta with frequent skirmishes, you could argue it's better than Arcane Comet, but strangely, its win rate is quite low.

(Probably because many people take the wrong secondary runes, and also because the real beneficiaries of Electrocute are Syndra's counters.)

This is the most basic Arcane Comet rune setup.

Its purpose is to gain early lane priority by poking with Q (Arcane Comet + Scorch + Conditioning) to pressure the enemy's health.

Compared to Electrocute, the advantage is that you can get more ability haste from the rune tree, but it's a shame that the ultimate cooldown is shorter with Electrocute. Since the Electrocute buff, I wonder if I should even take it... but there are definitely matchups where Arcane Comet is better.

For example, melee champions like Zed have ranged farming tools, so they don't give you good Electrocute trading windows early on. You need to take Arcane Comet and pressure them. If you can't pressure early, the lane priority shifts completely to Zed after level 6.

Strangely, this rune is performing better and better with each patch. Probably because short-ranged champions are more common these days, and with frequent skirmishes, it's easier to generate gold.

It's the most versatile rune. It suits Syndra well since she's a scaling mage with decent range. The damage is a bit lackluster, but since it accelerates your gold income to get items faster, you can ignore the rune's own damage contribution.

You can take Magical Footwear instead of Cash Back, Biscuit Delivery instead of Triple Tonic, and Cosmic Insight instead of Approach Velocity.

This is a rune you take against champions with longer range than Syndra, like Xerath.

Typically, long-range champions have poor gank setup, so you can freely use Approach Velocity. The idea is to trade with Approach Velocity + Arcane Comet, while sustaining with Font of Life + Revitalize until you reach Q evolution.

After Q evolution, you have solo kill potential and much stronger skirmishing power, so you just need to survive until then.

The screenshot shows the ability haste shard, but attack speed is actually better because if you lose the early level 2 push, it becomes harder.

It's also not bad against Viktor. However, since Arcane Comet can be dodged, it's not recommended against melee champions with mobility.

2. Items

This build maximizes magic penetration, making squishies scream and die. If you add Sorcerer's Shoes, most mages and ADCs take true damage unless they build MR.

The downside is the low ability haste, so if you can't burst them in one combo or miss a skill, you have a lot of downtime. Going Horizon Focus or Cosmic Drive as a third core can somewhat fix this, but the opportunity to do so rarely arises.

Usually, the third core is a survival item like Zhonya's, or if you have the gold, Rabadon's. If you need more magic pen, go for Void Staff or Cryptbloom.

If none of those apply, get Horizon Focus or Cosmic Drive to make up for ability haste.

This is an option to build Luden's Companion as your first core. Compared to Storm Surge, it has 10 more ability haste and the advantage that with Luden's effect, you can one-shot the backline minions with a single Q.

Luden's damage is spread out the more enemies it hits, so unless you hit a single target, its damage is weaker than Storm Surge. However, the generous mana, a bit of ability haste, and the convenience in waveclear are quite attractive. The Electrocute buff allowing you to cover damage from runes is a plus.

For the second core, you build Storm Surge or Shadowflame. Usually, you go Storm Surge due to cost. If you have gold and skirmishes are frequent, Shadowflame is more efficient.

Think of Storm Surge as better for sidelaning, and Shadowflame as better for teamfights.

The third core is similar. You can build the one you didn't build from Storm Surge or Shadowflame, or go with the usual items like Rabadon's, Zhonya's, Void Staff, etc.

This build has been a bit less popular this season. The main problem is the weak damage. Recently, the Seraph's Embrace - Cosmic Drive build has been performing better, so I recommend switching to that.

It's not unplayable – it maintains decent performance. Compared to Seraph's, it has a faster first core completion timing, so it has its own niche.

This build has a similar feel to the Blackfire Torch - Cosmic Drive build. The Lifeline effect from Seraph's Embrace and the movement speed from Cosmic Drive suit Syndra as an immobile mage, and the high ability haste increases teamfight stability.

It shares the downside of the Blackfire Torch - Cosmic Drive build: the damage from items is weak. You can cover it with the buffed Electrocute, but if you take other runes like Arcane Comet or Phase Rush, the lack of damage is very noticeable.

Even at the first core timing, there are many cases where you can't secure kills that you would with other items, so keep that in mind.

So Seraph's Embrace is most efficient in matchups where you have to play safe even after Q evolution (Irelia, Yasuo, Fizz, etc.). Since you can't overpower them with your first core anyway, you just survive lane and scale steadily.

For the second core, you can also go damage items like Shadowflame or Storm Surge instead of Cosmic Drive. However, Storm Surge's skill damage is a bit awkward, and Shadowflame often can't be built due to gold shortage during the build process. So Cosmic Drive is the safest option.

In fact, the more damage-focused a build is, the higher its ceiling but the lower its floor, and the more ability haste-focused a build is, the lower its ceiling but the higher its floor. So just go with what suits your preference or playstyle.

Since the removal of mythic items, it's practically impossible to get both ability haste and damage fully, so if you go Blackfire Torch or Seraph's Embrace, you think, 'If I had Luden's, I would've killed them...' If you go Luden's, you think, 'If I had Storm Surge, I would've killed them...' If you go Storm Surge or Luden's, you think, 'If I had Blackfire Torch or Seraph's Embrace, I would've had Approach Velocity up one more time...' Yeah, you're always stuck in this dilemma.

Usually, against squishy mages or ADCs, Luden's alone is enough damage.

I used to vary my build based on the enemy champion, but these days I just build whatever regardless. The Electrocute buff covered a lot of the damage gap.

However, against Yasuo or Malzahar, Luden's is highly recommended because it easily removes their passive.