Keep your lane not push, harass enemi with "Dark wind". Use "Drain" if you're low life.
Use teleportation for gank. You can do better gank if you tp on a ward in the grass.
If it's not possible to gank, you can go in jungle for give more xp at your team.

When you gank, start with ulti and launch "Dark wind" in first, and "Terror" in second. Instead of too much fiddle, use u're ulti for touch all the enemi team and not juste for focus one enemi. DOnt forget full pene magic build is for put low life enemi and not juste for one character. In teamfight, try to ulti when enemi cant see you cast it, or when all enemi are in same emplacement.

! : With this build, it's very probably you die in all teamfight, but this build can put all enemi low life and your teamate can finish the work easy, and win teamfight.

Put ward on the map for tp and gank easyer. The best emplacement for gank is Wraith spot, Nashor, Drake, and the two middle grass. Try to "Drain" their carry / support instead of tank / offtank. It's the same for "Dark wind".

Now you've to finish 4/5 item, it's very probably enemi bought negatron cloak or banshee's veil or other magic resist item. But it's useless face to full pene magic build. That's why this build is really nice, because in early/mid or late game, you ignore they magic resist and always put their too low hp (tank too).



I did this build after test too much build with fiddle : tank / tank + ap / full ap / ect...
In late game, you can switch Haunting guise by Rylai's cristal scepter.



For finish, sorry for my english but i'm french, and i dont speak english very well :/ .

Good luck and hf :D