I've been playing this class for about 2 weeks, tried the skills and learned to use them so many times and I feel like this char needs to be buffed and changed a bit. Since it clearly doesn't make sense with some of the skills it has.
In tiger stance, yes the bonus is quite cool but the skills in this tree just doesn't deal the load of dmg that it's supposed to deal. No ignore defense effect makes them quite lame dps skills that don't even work that well in either PVE or PVP. Penetrating Edge 3 and Death's Graps 2 have nonsense effect since it only silences for 0.1 second, interrupt casting would be ridiculous when normally you can hardly touch them in time when they start casting their spell, range dpsers and healers have so many ways to keep you slowed down or stayed in 1 place. Burst of Speed might sound nice but it lasts for only 3 seconds but it has 20 seconds cooling down ? To cast the skill and through its animation you would already lose 1 second of that tiny 3 seconds duration. A character using an owl transform can boost mv speed by 300 in 30 seconds and normal character would have around 650 mv speed so 300 would be around 45% mv speed in 30 seconds ? again I tried this skill and it's nothing more than a burden in skill slots (compare to other classes who can burst up the running speed for much longer duration).
In dragon stance, the stance itself has its own problem. it gives 40% more all def but takes away 32% damage and affects only yourself, compare to Path of Eternity of Soul Blade which gives 30% all def as well as physical protection and magical protection both get 12% bonus, and also affect a whole party but not just the skill owner (it doesn't minus any stat like Dragon stance does but adds even better bonuses). This is quite a huge disadvantage of Myrmidon class compare to its successor in human dual weapon type - Soul Blade.
In phoenix stance, Spirit Burn skill does not has the effect of -healing received like it's supposed to ( I tried this with a healer many times and same result happened, the effect of the skill is there but it doesn't make him heal himself less) Backdraft is a double edge sword which you stuns yourself and your opponent at the same time at the cost of your own hp, normally when I use it for quite often it doesn't even stun the target but still stuns myself and the anti-stun skills of Myrmidon didn't help protecting me from it. At the cost of my own 7k hp (which is around more than 10% in average for a character of dual weapon class with wings title and all stat gear).
The skills of Myrmidon overall are quite under-powered compare to many classes (I will not name the OP classes here as this is the main focus on how to make Myrmidon better not to flame on other good classes) Changing stances to fight in a combat is hard enough when skills are limited to which stances you are using, not to mention the skills are relatively weaker or, to be honest, miles behind some skills of other classes.

For the reasons above, here are my suggestions for improvement please take into account if you care for balancing the game:

Penetrating Edge 3 instead of silence for 0.1 second, it should be ignore defense for 20% (it's quite a decent figure, not so high but it helps buffing up a bit the skill)

Death's Graps 2 this skill has 12 second cooldown so for such long duration instead of silence for 0.1, an effect of ignore defense 20% and stun for 1 second should be legit for this dps tree.

Dragon Stance this skill should not minus damage or not that much ( currently 32%) damage for the reason I stated above ( Soul Blade with the same skills without deduction but even better bonus status)

Below are 3 magical skills that Myrmidon has in Phoenix Stance which don't really work well like they should be ( damage is not even decent and effects are not really relevant):

Blaze should change the melee range from 5.0m to 8.0m and Magic damage absorb from -20% (of opponent) to -30% since it is just a debuff skill that doesn't do much damage (Myrmidon is a physical class, the damage of magical attack is nothing compare to its physical attack so even with such long range and the bonus this skill still doesn't make a big difference)

Spirit Burn this skill should be changed from 7 seconds cooldown to 5 seconds and melee range from 7.0m to 8.0m so that phoenix stance's skills have a better chance in dealing damage.( Same reason as above, as a physical class, the damage Myrmidon deals in magical type is quite low)

Back draft it should not stun the Myrmidon using it but stuns the opponent for 1.5 second and melee range from 4.0m to 7.0m (As mentioned the cost of casting this skill is more than 10% hp of normal Myrmidon's hp and it always stuns the Myrmidon but it often doesn't stun the opponent, at the cost of such disadvantage improvement is needed)

Although the Magical skills above are with AOE effect, but the radius is quite small and usually if opponents don't stand near the back of the target they just doesn't affect them at all.

Please Sedy, help us balance the classes better