Here are my Power Rankings for Semifinals:
2. Royal Never Give Up
3. SK Telecom T1
4. Team WE
Don't get me wrong every team in Semifinals deserves to be there and are all showing that this tournament is still only just begun, i.e. there's a lot more League of Legends to be played, but it is clear that certain teams look stronger than others. Though Quarterfinals showed shakiness in SKT and WE's play, if anything can be learned from groups it's that a week can make or break a team. It's hard to decide winners and losers based on Quarters alone, and that's why I'm not saying that anyone is going to win, but I will instead say that they all look strong but some are cleaner than others.
Predictions going forward: I think that SKT vs RNG will go to five games and the winner of the 4th will probably decide the series, and that WE and SSG will be either a 3-0 sweep if Samsung wins or a 5 game set if WE wins. Either way we're in for a long and close Semifinals, and an even closer Finals. Stay tuned.