As kha you will want to use your q as much as possible while farming to charge up your tear. The faster you get your muramana you better you will be able to burst the other teams adc or apc. Although make sure you still have mana for a gank. Use your w on waves of creeps late game

For your runes you can take attack damage reds or armour pen reds, armour yellows, magic resist blues and amour pen movement speed or attack damage quints.

Take 21 offence and 9 defence its quite simple. or 21 6 3 but 3 points into wander if you want but I prefer 21 9

There are 2 ways to gank with kha that are very affective. 1st a in lane gank this is really affective agaist champions like mord who have bad cc. To do a in lane gank get your top or bot lanner to push so you can sneaked into the bush. then get your top or bot lanner to use cc such as a stun or a slow then you jump from the bush and burst. 2nd you have your tri gank this is really affective if you are using flash. what you do is run though the enemies jungle go into the tri brush then ult + flash then jump. Make sure you know you can get the kill because this gank when used can cost a flash. BUT if you want you can use your ult on e so this gank will not cost the flash just cost the ult.