"Ketar is an interesting set which actually looks better in hand than in pictures (as with most sets). However he (she?) is by no means the best of the creatures.
The build is fairly simple, with the complexity mainly being in the torso. While I, as a gen 1 Bionicle fan, appreciate the more technic-based build, it isn't great if I'm perfectly honest.
The function works well and is fun to mess around with, however it has no friction and is not the most inventive, though it does still work in unity mode which is a plus.
The overall appearance of the set is good, much better (as I said) in hand than it appears in pictures. The tail, however, is very oddly designed and the two crystal blades are long and a oddly placed, though I don't actually mind how they look.
The unity mode with Pohatu, while many have said looks bad, I would actually say I like. If you bring the tail right down, position the legs over Pohatu's shoulders and around his waist, and bring the blades forwards and out at an angle, then it looks pretty cool in my opinion and Pohatu gains a pair of blades and a tail.
In conclusion, I would recommend you buy this set if you get Pohatu Uniter of Stone, but on its own there are better creatures for you to buy,"