I love assassins and anyone who can combo 100-0 champions. But lately I feel like alot of assassins have been nerfed and even mages that could 100-0 have been toned down. Is there any reliable champion that can consistently "one-shot" without being ridiculously fed?
Yeah, I haven't had that feeling recently where I throw my skills on someone, shout "DELETED!" and cackle. LeBlanc is pretty alright, Talon and Rengar have their moments, Syndra and Annie are pretty strong... I personally like Xerath these days: he's not the burstiest, but with two long-ranged CCs and two super-long-range damage spells, he does work.
League of Duty
Is there any reliable champion that can consistently "one-shot" without being ridiculously fed?
Why...? Why would you ask that? You're literally (hate using that ironically) asking for an easy champion to delete people without being fed.
Play something that either requires skill, risk, or work in order to do that. Don't look for the easy way to be the annoying player that nobody likes, please.
Try something like 
He's strong, one of the best junglers out there, but he still requires some skill and effort to reach his potential.
Be a true man.
Play AP Ezreal. The poor man's LB.
Almost all burst champions can 100-0 people that don't build defense.
I've been playing a lot of annie, and it's extremely easy to 100-0 as her. Generally once get rod of ages and boots 1 I'm able to 100-0 the opposing laner/any squishy with ignite, I then rush a needless rod and can 100-0 without ignite.
Nidalee is one, another is Zed.
Enjoy your freelo.
