This is a build my friend discovered himself then spread the word onto me. Thanks @LubedKagaroo. I could not find this build on mobafire so I am here to spread the word! This is an OP late game build with Ms. Caitlyn! This guide will keep receiving more updates once I see more attention being brought to the thread. Please let me know if this works for you or if it doesn't. :) Feedback is appreciated.

Every 7th shot triggers the extra damage. With Runaan's Hurricane, each of the extra arrows shot count as a shot as well. So 2 normal shorts of your gun would count as 6 shots toward getting that extra damage off. The Runnan's and the Berserker Grieves will be good enough attackspeed to keep leeching life. Especially with those 2x Bloodthirster you built! This also is very good at melting down multiple targets! Make sure to use this new found power in mainly team fights or cleaning up! You do not have much sustain! So be warned! Again best used in team fights and when not being focused. When hitting multiple targets should also give you crazy amounts of HP!

Some of the tricks given below will be obvious but you need to make sure you do these certain things well!

FARM! Always the first priority.

If you can play aggressive! Make sure your support can do that as well. Preferred aggressive supports could be, Thresh, Taric, Lulu, Sona, Nidalee.

Poke the enemy like hell especially with that extra damage from your passive but try not to do it often enough to miss last hitting creeps!

Place those traps in replacement of wards if they are not available at the time!

Place the traps strategically. Possibly when dueling the other ADC, place the trap behind them or on them to prevent them from running.

Take advantage of that long range your mother gave you!