Blademaster is one of the best classes in the game. From an escape perspective, the only downfall is you are dependent on venom. I myself have solo’d the surge and The Line (to name a FEW) as lahni on master and very few classes can even do that in general. I could say much more but that speaks for itself.
If someone isn’t good as Blademaster they probably need to work on their movement skills and dodging enemy meles, things of that nature.
My friend @RelaxingKoty is probably the best lahni in the world and he told me that scions only mele with their left arm so going left as they swing left is a big detail you need exploit.
In a 3 person game most escape maps are too easy (on master) relative to the characters used so you might be outside of venom a lot.
Long story short, the ONLY downfall is you need to embrace venom.