Yetis.  They're pretty bad.

Not at all.  They need to have every ability viable independent of the other ones.  Synergy is fine as long as it doesn't guarantee one ability is always chosen regardless of your build.  All the abilities should be good enough to be picked.

Yetis are essential when you are fighting a oak or erebus other than that, they are great to destroy buildings and as a independent atack force, they are not used a lot but not because they are bad but because people prefer the duelist sedna as it is less micro intensive, fully upgraded yetis can fight towers and other acreeps ont hier own especially with wild swing.

hmm i want to make a new build for  sedna

queen is hard to play  espically ifyour new to gaming   i found  that the only thing i think is op is when she spams sheild

The problem is, a good sedna/qot team with good players will push you so hard in the beginning, that you just can't do anything. How are you going to handle heal/shield? Yes, later you can beat them, but hardly in the beginning. So what are you gonna do? For instance, on PRISON, which is really small and open, they will simply harass you, keep you from exping and away from the flags, and if they score some kills, they will have an even bigger advantage. At the point where you can beat them, they will be so far ahead, that you just cant catch up anymore. They will have more cash, more warscore. You just lose. Of course you can win if you are the better team or get lucky, but it will be the exception.

It's like on small water maps in SUPCOM. An equally skilled AEON/SERA player will just domimnate the other races!

The skills have to be balanced in a way, that any team combination and any single DG is counterable.

I actually played a few great Queen of Thorn players in team games.  She can be very good and unstoppable just like all other demigods in the later levels.