Rengar is, as you all know, a strong champion. He's been jungling and surprise ganking everyone with his abilities. BUT! have you ever thought about playing him as AP? This build will make him Heal alot and do lots of damage with his Battle Roar, a roar that shakes your enemies in fear.

The rune choices i've taken is for making him sustaining in Top, being able to deal with champions such as jayce, darius and all of the AD Top champs.

These masteries are for ap damage dealing and survivalbility against top lane. Ofc giving him defensive masteries so he gets some health extra because his Feroicity version of his Battle Roarheals % max health

Items i choose was for movement speed in early, pots are ofc for making him more sustain, and later on building the kage's lucky pickfor extra gold while in laning phase. The will of ancients is for healing each time you use battle roar, and spirit visage increases the healing from 15% to 30% of his max health. The other items in the end of their builds are mostly for DMG dealing.

The skill sequence is having early Battle Roarfor early armor bonus for 3 sec and dmg dealing. Savagery is for being able to last hit minions and hit the enemy. Even as AP rengar your Savagery still do lots of damage. Bola strike is the 3rd skill i take, taking all the 3 diffrent skills in early at lvl 3 will give you the chance to increase ferocity faster, this will give you the chance to earn ferocity fast and be more flexible when using diffrent abilities. And ofc take your Ultimate at 6,11,16 as every ultimate. But remember you can get to use a 3rd Battle Roar with the Ultimate after you've used battle roar 2 times before.

Flash is mostly for Running away or engage or mostly chase. Ignite helps you to get your kills or weaken lifesteal/spellvamp from your opponents.