This week champion rotation is the folowing: 

1. Blitzcrank: A tanky support, very usefull on laning phase, that       depends on a skillshot to iniciate. Has a silence and a knockup, that can be very usefull on teamfights
2. Dr. Mundo: A very resistent champion, good for jungle and for top lane, slow on his Q and a passive and ultimate that heals him. He has to be on your frontlane recieving al the enemy attacks.
3. Nasus: The only thing you ahve to have in mind when you play this puppy, is to farm, farm, and farm. your Q grows stronger the more you kill minions with it. Late game nothing will stop you, and you will be able to farm champions.
4. Gragas: A very versatile champion that can work either on mid, top or support. Ypu can go straight up damage, or go for a more tanky build. 
5. Kog'Maw: The cutest champion here. A heavy dps marksman that melts down the tanks late game, but is very unmovile, and is not very good on early game.
6. Urgot: One of the least played champions on the league. Is short range on autoattacks, and quick mana consuption makes him not a common pick. But if you survive laning phase, later on is a beast and can outduel almost anyone.
7. Trundle: The troll king can work very good as a jungler, or as a tanky fighter on top lane. His E allows to gank very good, and his ultimate and Q allows him to duel anyone without fear
8. Skarner: This champion was one of the favorite ones on season 2 and early season 3, but slowly began to became less used. Now with his recent changes, fits this meta very good, with fast ganks that almost always finish on a kill. You can go hybrid damage on him, and destroy your enemies on any stage of the game.
9. Xerath: The most powerfull champion on the league acording to the lore. It has long range abilities that can harass your enemy on laning phase safely for you, and your autoattacks restore mana. What could be better? A very long range ultimate to help other lanes? Check. One of the longest stuns in the game? Check. Just go and try it.
10. Ziggs: This yordle will destroy you before you notice how cute he is. Has a long range poke, and a secure scape, and a very very long range-area of effect ultimate, the only con, is that he eats lots of mana early on, and you will need blue buff, or chalice of armony