I would like to promote this guide, i infact made up my own build and it just so happens to be nearly identical to this. This build is just awesome early-mid-late game and have never had a game were i had negative ratio kill/death. One thing i might change tho is for runes marks-seals-gylphs-quints should be replaced with crit-attckspeed-attackspeed-crit respectively. With these runes they help me early-mid game. this will solve the issue with buying a crit item first, instead with 12% crit from runes, my first item is a vamp scepter so i can start using enrage right away at lvl 2. With about 15% crit and 12% lifesteal right from lvl 1, laning is very easy even with a caster/ranged since u can lifesteal your health back with minions.

As for spells i use flash and cleanse. being a extremely high dps i get stunned and snared alot so right into a battle i can flash or run to the squishies hack them into pieces with about 3-4 autoattacks and use cleanse whenever you get stunned. save your stun for initiating or people who run away.