Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Simply machine to push middle in 5 vs 5. After destroying 2nd turret call your friends and push middle to destroy 3rd turret or you can play with your enemies and go clean up top/bottom.
1. Learn accuracy with your grenade (this is your main weapon).
2. Try to stand as long as possible (you can push slower after 1st turret) to gain enough gold to Frozen Heart (ability duration will help you be one man army with multiple enemies).
3. Don't stop killing minions (gold).
4. When tank or short distance assassin catch you near throw grenade on yourself and run.
5. Use clarity with smartness, on early levels you gain some mana.
6. Grenade is taking some damage to turrets.
7. Evolution turrets can help you destroy turrets faster.
If you have problem in mid with your enemy, wait until 6th level and call someone to help you kill mid player.
And most important thing: Don't die and don't run for kill. You are not for that in this game. Just push minions to destroy three turrets in middle, or mid/bot/up turret at the beginning.
With worst regards and bad luck in game playing with me,
PS: Kiss me where it smells funny. :_)