The idea of this build is to make your %Charge Sunfire do the most damage possible and burst with hits on %Nova Orb.

Synergy

%Charge Sunfire is an ability so it will benefit from the damage boost of @Sunweaver . %Nova Orb will hit harder as well.
You don't need to hit %Sunspear's Rifle attacks to trigger @Sunweaver 's missile, they trigger on your %Charge Sunfire hits, after you dash, ult or cast %Nova Orb.
If you detonate %Nova Orb with %Charge Sunfire, you'll do massive AOE burst damage, with the enhanced ability damage and @Sunweaver missile.
Unlike with @Harmonic Edge, if you miss the attack, your @Sunweaver proc will not be lost, making this a reliable source of damage. At level 3, the missile also heals you. Huge value item with crazy synergy on Saros.

Grips

@Burning Palm is mandatory. Your %Charge Sunfire hits and every other ability will trigger this and slowly shred tanks.
@Feytech Claw for more burst damage on %Nova Orb. More damage on %Charge Sunfire too.
@Longclaw Optics take this if any of these happen:

The endgame is on abyss. The extra range on %Charge Sunfire is huge and can annoyingly poke enemies on islands.
You have a #Money Tree. The extra range allows you to keep hugging the tree and get infinite mana for your shots with @Forest Blessing.

Don't take @Frozen Palm, doesn't really help hitting your shots, the effect fades between shots, especially if you are not %Ionized.

Relics

@Sword of Seven Suns is mandatory, the damage boost affects everything on Saros' kit and the penalty is almost insignificant, you are crippled when using %Charge Sunfire anyway.
Replace @Sunweaver with @Refractor, ideally at level 2, if you can afford it and are expecting more close fights, where the damage from %Ionized %Sunspear's Rifle attacks is important to take out enemies.
Replace @Sunweaver with @Ardent Songbow if the latter is level 3. It's the most broken item in the game currently and reducing the cooldown of your dash and %Nova Orb is huge.

Kicks

@Rocket High-Tops are great. This build lacks mobility, so the extra dash distance is useful to kite and to secure those wall stuns.

Perks

@Glider Booster and the perk that regens armor out of combat are mandatory.
@Forest Blessing gives you tons of mana to spam %Charge Sunfire if near a tree or if you manage to get #Money Tree.
@Oracle Immunity if none of your teammates took it.
@Grace for more movement speed.
@Generative Elixirs if you want to abuse its tech with items like #Scan Grenade
@Heal Receptor when playing with a healer.
@Nocturnal is also very good.

If you manage to get @Renewal , combo it with @Rapid Metabolism .

Swordweaver Saros