See this is your problem. Just because a champion is off meta doesn't mean the champion is bad.
A good Nami is amazing, ask people like Deep Terror Nami or RiotKatyKhaos. Nautilus is an amazing tank, even stronger now as a full tank then he has been in the past. Malzahar* is a good all around mid laner, especially against high mobility people like Yasuo or Yi, Rek'Sai builds like a tank and has regen in he kit, so I don't see the hard to kill, Cass is still very strong when you get time with her under your belt, Braum is a staple in the LCS, and a very capable support for almost any comp, Zilean can be played mid as well as support, and either he does excellently (also recently played in the LCS), overrated doesn't mean anything -- Thresh is a good all rounder support pick, Tahm is amazing as a support when they know what they are doing (again, look to LCS), Caitlyn is a good lane bully with a strong late game, Ez and Varus are great for poke comps (Ez has a stronger late game, Varus has better utility, one of the reasons he's see more in mid), Ahri is still as strong as and a good pick as ever, Shen is an amazing peel tank, split pusher, and tank duelist.