I don't know... !PIZZA 3 Hand Tossed has some great people in it as well, I might be a little biased on it though... :)
I know there are a tone of legendary summoners there that are amazing, but I think I have to go with Bortus, mostly because as fighting in those lower levels you see a ton of wavesmiths. So fighting them off is easier with him and a little bit of attacking with sneak. The first time I finally beat a wavesmith is still in my head using Bortus, so I think he might be on the underrated side, but awesome to have!
Splinterlands name: Kqaos
We are but a slice of the great Pizza pie...only together can we unfold our true tastiness.
I'll often curse when facing Bortus with Alric!
The Wavesmith is a great card, usually gets a place in 20+ Mana matches when Water is viable.
!PIZZA