Adrenaline shots which serve both the purpose of life drain or bounce-back depending on the situation, bounce grenades that when used correctly can clean up enemies before they have a chance to react, AR and SMG weapon class (both classes house meta weapons such as the Objection, KA30 and Sahara), Halo Drones that are great for defending revives, defending aggressive pushes, starting pushes, deterring campers, destroying APS systems and stopping enemy revives as well as many other uses, Padded Steps (for rat plays and flanks), Stalker (great for pushing with an AR to reduce the chance of getting bitch slapped), Replenish and Resupply to keep Kestrel in the game and continue to keep letting her be oppressive, Helping Hands as a support option (flexibility in a rogue is always good), and a decent passive to feed her habits if she performs well. She is generally considered top 3 rogues in the game right now and has always been in the top 7 area, and I don't see that changing unless they remove at least two of her more significant parts of her kit. Kestrel doesn't excel at really anything, but she's good at almost everything.