the 100 follows through, not every disaster gets stopped at the last minute, they let tragedies happen! the thing with Kane is he's not 'evil', he doesn't *want* to kill hundreds, but he's looking out for the rest of his people, and he's willing to be ruthless to protect the majority. the more they delayed the culling, the more would have to be sacrificed, so him wanting to get it done sooner rather than later was him trying to save as many as possible, having accepted that a culling event is necessary/unavoidable. also the episode descriptions for the 100 tend to get pretty spoilery, it's up to you but i personally wouldn't read them before watching the episode