I delayed getting Avyx, my biggest mistake this season. He is actually a surprisingly good hunter. Avyx vs. Borgian, I would pretty much pick Avyx every time. In fact, there are actually a few situations that I would actually pick Avyx instead of Necryx.
First, he is a pretty decent lead. Even with no white spells, he can often take out the front three towers on an island with TF, even with a blue mage present. Equestor and Borgain can only pull this off with low level towers that can be killed by a single bolt.
As a follower, Avyx’s focused DPS is really hard to top, and he doesn’t unsand towers an accident when following Necyx. Whereas on strong bases a lot of hunters can feel “out of breath” as they try to take down the towers, Avyx takes them down without a pause. And at one rage cost, you can practically TF through an entire base.
The most important thing is to load him up to the gizzard with healing mark runes. With really good healing mark runes, he can regain about half his health for one rage. His mythic rune is also a must have. I do not have it yet, but you never can have too much DPS.
One place where Avyx really shines is when it comes time to kill high level farms and mills. For most farms near my level, and up to 30 or 40 levels above me, TF may as well be death gaze. Necryx and Borgian, on the other hand, tends to have trouble with high level farms. And as for sorcerers, they are among the easiest dragons to stop with hammer spam.
Although Equestor can deal a lot of damage, with the summoned familiar, thunderbolt, and fire attacks combined, all this damage is spread out, save for the familiar, and the familiar cannot be controlled by the player.
So in the end, I think Avyx was a hidden gem this season. Early on, I had dismissed it as well nigh useless, and actually went for Leos instead. After hearing reports from high level players that got him, I decided to give him a try, and I definitely do not regret it.