Grand Master Yon

he's not on top of the mountain, he's in a tiny cave, close to the top, the entrance is at 35,74 (Kota Peak) I tend to take things literally, so if someone says he's at the top of the mountain, that's where I look LOL he's not there ;)

Here's a guide to SOLOING this tamer with a single pet - the [npc=68659]. Using this method, you can carry low-level pets and power level them.

All you need is a level 25 [npc=68659]. You can chose any filler pet for slot 2/3 including 1 (or even 2) low level pets to power level.

The set-up you want for your idol is:

Here is the setup you want to run:
Slot 1 - [npc=68659] : [petability=406] | [petability=453] | [petability=490]
Slot 2 - [Carried Pet]
Slot 3 - [Carried Pet]

Enemy Team Summary
[npc=66721] : [petability=581] | [petability=524] | [petability=170]
[npc=66720] : [petability=162] | [petability=360] | [petability=159]
[npc=66719] : [petability=541] | [petability=539] | [petability=163]

Strategy
This fight is an absolute joke for the [npc=68659]. Each enemy pet's damage is largely mitigated by [petability=453], and each has a big ability that can be blocked by [petability=490]. The beauty of [petability=490] is that is always goes first, and also will block EVERY direct attack that occurs in the turn that it is used. In addition to all this, every time an enemy is hit, the idol, as a Humanoid pet, regenerates 4% health. As a result, I often end off killing the last pet with 100% health.

Piqua
Piqua starts with using [petability=524], then [petability=170] which takes two turns (one to fly up, and a second to fly down and deal the damage). It's a simple matter to use [petability=453] on Turn 1, then [petability=490] whenever he is about to come down from [petability=170] (Turn 3). After [petability=170] has been used, the next ability is [petability=581], which takes 3 turns. ALL DAMAGE from this ability is mitigated completely, making this an excellent time to switch in one of your carry pets*. Use one attack with your carried pet, then switch back to the idol.

Use [petability=406] to deal damage, and [petability=453] on cooldown to finish off Piqua, using [petability=490] when necessary to block as noted above.

Lapin
Lapin will use [petability=162] and [petability=360] which will hit your idol and take a bit of health off. Simply continue damaging as noted above with [petability=406] and [petability=453], and [petability=490] to block the [petability=159] ability (also a 2-turn ability like [petability=170]). Isn't too hard to finish Lapin off as well.

Bleat
Bleat will use his namesake ability ([petability=539]) to heal himself intermittently. Otherwise he uses [petability=541] (yet another 2-round ability!) Which should be blocked with [petability=490] on the second turn. [petability=163], his other ability, is essentially the same as [petability=581] - 3 turns, with ALL DAMAGE being completely blocked*. This would be another spot for you to switch in a carried pet, if you didn't do it when fighting Piqua, or if you had a second pet to carry. Once again, use the same damaging abilities to whittle Bleat down.

There you have it!

*Do note that [petability=453] will mitigate the multi-round attacks like [petability=581] and [petability=163] completely for most pets, but I have found that Elemental pets will take some damage from those abilities through the [petability=453]. This is because Elemental pets ignore weather effects, including [petability=453]. As such, your carried Elemental pets may need to be level 5 or so, in order to withstand the damage for a couple of rounds.
Alternatively, you can time your pet switch so that you catch the last round of a multi-round ability and the round in which your low level pet attacks is one where the enemy is using [petability=541] (Round 1). This means that your [npc=68659] will take some damage when switched back in, but that is not a big deal since he takes so little for the rest of the battle!

Finding this NPC was very frustrating. He is in a very small and obscure cave in a dark portion of the mountain, not at the very top. In this image I am standing at 35.9, 74.6 in Kun-Lai Summit, facing exactly north, exactly toward the mouth of the cave. Fly to these coordinates and land down on the snowy platform where I am, and you will see the cave opening if you face north.