rework vamp spell

Hi, I wanna talk about the working of the spell vamp because I think it needs to be balanced. The spell vamp items are unpopular except on , and and I wanna give these two items some more importance in the game. The biggest problem of its working is that you only get 1/3 from the life steal benefits on AoE spells. This restriction is justified against minions, otherwise a mage will gain a too massive regeneration. For example: lux hits an enemy with her ultimate and at the same time hits a whole minion wave, her regeneration would be too massive if the the 1/3 restriction didn't exist. But it's not justified against champions, so my proposition is to change it from 1/3 to 2/3 against champions (and big jgl monsters like drake and nashor).

The spell vamp runes are just bad. If you compare the combination cost of and you will find that the life steal cost is twice higher than the vamp spell. So the spell vamp runes have to be twice higher (3% vamp spell for 1,5% life steal) and same for masteries(1%-->2% vamp spell).

With these changes we will see cassio, kennen, ryze, annie, katarina(more often), ... with spell vamp. I don't think it will be OP for some champs, vlad will maybe become a little too strong, but let's just see what happens.