Hi!I'm GVT.Lotus, the Mid laner of GV Thunders(Vietnam), and today I'll show you how to build Viktor - one of my favorite champions. First of all, if you're lower than Gold V, then Viktor is not for you. This champ requires excellent control and reflex, not a champ for newcomers. So let's begin examining his abilities, and see what can he bring us!

Pros:
- Excels in laning and trading skills
- High burst damage
- High Auto range (525)
Cons:
- Low mobility due to no dash/blink/movement spells
- Not very much CC
- Requires high level of control and reflex
- Usually lack of resistance due to losing 1 slot to Perfect Hex Core

Of course Flash takes one slot. In the other slot I recommend:
- Ignite for aggresive players
- Heal/ Barrier for defensive players
- Exhaust versus heavy AD Assassins such as Zed / Yasuo / Talon / Kha'Zix /.....

Other options
Greater Marks:
- 8x Greater Mark of Magic Penetration + 1x Greater Mark of Critical Chance
- 6x Greater Mark of Magic Penetration + 3x Greater Mark of Attack Damage
Greater Seals
- 5x Greater Seal of Scaling Health + 4x Greater Seal of Scaling Armor
Greater Glyphs:
- 7x Greater Glyph of Ability Power + 2x Greater Glyph of Mana Regeneration
- 6x Greater Glyph of Scaling Ability Power + 3x Greater Glyph of Magic Resist
Greater Quintessence:
- 2x Greater Quintessence of Ability Power + 1x Greater Quintessence of Scaling Mana

Siphon Power is your main damage dealer so it must be maxed first (lvl 9), then I recommended maxing Death Ray. Take only one point of Gravity Field at lvl 3 and max it last.

Evolution Sequence:
Of course, Siphon Power first. You usually got Hex Core MK-1 at lvl 4 to 6, so at this time your Siphon Power is your main source of damage. Evolving this first and 30% movement speed gained will helpyou very much in laning and escaping.
Then at Hex Core MK-2 (usu lvl 9) it is up to the situation. Evolved Gravity Field act almost like a minimized Orianna's Command: Shockwave, while evolving Death Ray gives you more damage in combat.

Starting items: I'd prefer Doran's Ring but you can also choose Boots or Ruby Crystal for a better laning phase(situational).

Before lvl 8:

Your focus at this time is to finish Lich Bane and upgrade your Prototype Hex Core to Hex Core MK-1. Lich Bane is a very important item since it helps Viktor ultilize his Siphon Power - Auto combo. At this phase, if you have more than 1000 gold when you come home, UPGRADE IMMEDIATELY! Else, buy yourself a piece of Lich, and continue.

Lvl 9 -> Lvl 13:

You must finish your Liandry's Torment and Hex Core MK-2. If you're very green then you can go straight to Perfect Hex Core, else just finish your Liandry first

Lvl 13 after:

Finish your build. Remember to finish your Perfect Hex Core after finishing your 3rd item (usu Zhonya's Hourglass). You can build aggresive or defensive depends on the situation.
Optional items:
Will of the Ancients or Hextech Gunblade if you want the Spell Vamp
Banshee's Veil instead of Rylai's Crystal Scepter for more defense
Void Staff or Abyssal Mask if the opponent are building too much MR

Laning phase:
- Don't hestitate to trade skills with your opp. The shield from your Siphon Power will give you an advantage.
- Try to corner them and force them to lose CS.
- Be careful! Since Viktor has to escaping skill, he is an easy target to their jungler.
Combo:
Gravity Field - Siphon Power - Auto - Death Ray - Chaos Storm
Then use as much Siphon Power - Auto as you can.
* Stay safe! Viktor is way to squishy to jump into combat. Positioning is very important!