lvl 51 can suck it

[Tethler]

The aviaks in TD might still be good till 52-3. I think I personally quadded them from 46-52. That was like 2 years ago though, so I don't really remember that clearly.

[Insomnia]

You can grind the nobles in HHK until 56 if you really wanted to. I had a stretch of a few weeks where I had little time to play but still wanted to grind somehow, got levels 52-56 off them didnt really take that long either iirc cause HHK has a very high zem.