Hi everyone!

Firstly, you have to start of cosmic belt TIER 2, it costs exactly 1250 gold. Most people have mod for this item, which gives +75 bonus health. Later need to rush Starheart (buy mod for price reduction -300 gold for last tier) to improve your damage and get some kills to feed yourself. Psi-simitar is great 3rd item in my opinion. Tier 3 gives great extra power damage. DO NOT FORGET TO USE 1 BASIC ATTACK AFTER EVERY SKILL. You passive in combination with Psi-simitar is really amazing. 

*If you have problems with building startheart (not enough money, match goes badly) you can buy Radion Shards and sell it for whole price when you got enough money.*

Use Q smart, try to hit oppoment every time. Don't waste your mana points. With this build you can easly LOOSE YOUR MANA very fast but it gives you tones of damage. Control it. If you cant aim Q very well yet and have a lot of misses, buy Doctor Destiny's Dreamstone TIER 2 after Cosmic belt TIER 3, before starheart. Try to upgrade your dreamstone if you see it does good for you. Dreamsone TIER 3 (1750 gold) should finish your mana problems but it's very expensive - buying it makes your power damage lower in mid game.


Other items are optional. Depends on what type of champions play your opponents. 

Basic combos I recommend.

For tough opponent 1vs1. 

Q -- > basic attack --> E --> basic attack --> E --> basic attack --> W --> basic attack --> Ultimate --> basic attack --> Q (if no cooldown)

Chasing

Q --> ulitmate --> W --> basic attack --> E --> basic attack --> E --> basic attack -- > Q (if no cooldown)

In team fight to finish fast focused opponent by your team. 

W--> ultimate --> Q

If you have a huge damage and enemy has low amount hp and low def (assassins, ad carries and others paper types) it's enough to use:

Q--> basic attack --> W --> basic attack --> Ultimate --> basic attack --> Q (if no cooldown)

The combination E --> ultimate use only if you need to save your team mate or get somebody off the turret. 
Greatest one is W --> Ultimate because does tones of damage. Best time to use it is when opponent has lowest health. 

Thank you guys, I hope guide was helpfull!
See you in game!