Explanation on why this works:
Patch 13.10 brought us new views on some items, between all the adc and assassin parafernalia we stumbbled upon trhee changes that are curious:

• Lost Chapter being 200 gold more cheap.
• Imperial Mandate being now a legendary item.
• New item called Echoes of Helia.

Lets get into this and explain why this Viktor support build is not trolling and fairly affective into comps that need what Viktor offers.

--First off all: why these runes?--
The main rune tree of Aery is just for consistent poke in lane. You could even change it to Arcante Comet or even FS and take cookies for the mana sustain in lane in early levels.
But the nub of the issue here are the two runes in the secondary tree:

• Font of life: your teammates heal when hitting impared movement enemy champions by you.
• Revitalize: a buff to shields and heals to allies below 40% health.

And you all will be wondering "but Viktor does not have any healing or shielding in his kit. Well he has Q shield but only to himself, this is bs!!!" And you'd be right if it wasn't for some crutial information I have to give you next.

--Itemization and synergies--
The items to rush are the following in the same order as displayed:

1. Ionioan boots of lucity. The CDR is fundamental in this build as we will become a Slow CC Machine Herald.
2. Imperial Mandate: You will already proc the item with W so it is a huge buy rushed after boots as you will get much heals out if it if your allies hit the slowed and stunt enemies.
3. Echoes of Helia: After Mandate you should already have W evolve and proc both items with ease.

Now, why does this build works? Which are the synergies between the items, the runes and Viktor's kit? Lets delve into it point by point:
— First of all: the main point in this build is to get W evolve as soon as possible to get the advantage of you Font of Life. A thing you can already do by using you W at any moment, but if you, like me, are used to play Viktor, you will now that W is a clunky ability that is hard to implement.
With this W evolve you will proc you Imperial Mandate buff to allies, as well as with your W alone, which is a reason to buy it first item before Helia, since you can use it more efficently without you W evolve than Helia.
Now,when all of this is set up, a sinergy emerges:

1. Your Helia stacks up to two times when hitting enemies.
2. With AoE slows in every ability you proc Font of Life as well as Mandate buff.
3. With Font of Life on, you heal your allies when they hit the slowed enemies, consuming the 2 stacks of Helia making the heal of Font of life bigger, as well as dealing extra damage to enemies near.

As you have high CDR, your abilities are on a low cool down, and maxing W second gives you more opportunities to heal you allies and damage the enemy team. Your perma spam of abilities from a safe distant makes you a nice playmaking AP crowd controller support that has hella good heals for your team.

If Viktor team fighting was nice, now its even nicer as a support!