Akali is the top counter jungle and mid gank assassin. She can get in and get out. She is really good 1v1 and maybe 2-3v1 if fed. Katarina is the top lane gank. She could also counter top jungle if Akali is busy with mid. She has the ability to poke constantly with her knife throw; giving her the advantage of range between her and the melee top laners. Nocturne is also a top lane gank. His purpose is to get to lvl 6 as fast as possible to limit enemy sight so they won't see any ganks coming. Rengar is a bot counter jungle and bot lane gank. All he really has to do is sit in the bushes and wait for an enemy champion to pass by and then leap on them and kill them. Nidalee is the troll and bot lane gank. I chose to give her spear toss for is for this reasoning. If an enemy is getting away all you have to do is wait for them to pass at low health and spear them for the "BOOM! HEADSHOT!"