I already tried it with a polearm, spear and sword, still the same.
Blademaster Stances
likewise
Okay. Read the help files again...pay particular attention to the powerstrike requirements.
read it a ton of times...but doomsinger is for two handed weapons...it seems to work when it kicks in, ie you hit for max rolls, but when it fails you scratch, thats hwo i always saw it. i also thought it sometimes throws in an extra attack....but i think im wrong. but mines mastered and i still get a lot of scratches and grazes. and it never sings 
Doomsinger and Powerstrike are totally different from eachother, and neither work with one another. From what I see, Doomsinger is an EXTENSION of powerstrike with two-handed weapons. Usually, you could only powerstrike with two, one handed weapons. But, with doomsinger, which is basically the sance 'Powerstrike' is specifically for two handed weapons. That being said, you won't ALWAYS roll for the maximum damge, but when you do, you'll be powerstriking. When you're not, you're not doing anything put tapping your opponent with your weapon. (I need to go and look further into this, now I'm beginning to wonder..)
Doomsinger - While under its effects the blademaster further extends the principles of powerstrike, moving and attacking in harmony with the weapon's natural frequency.
Powerstrike - A successful powerstrike requires a second weapon to feign and setup the hit. This skill will only be used when you hold two weapons.
It would seem to me, since you don't appear to dual wielding in your log, that you aren't powerstriking. If you aren't powerstriking, then it would seem from the helps that doomsinger isn't going to go off either.
Bladelore stances:
Bladestorm (double weapon)
Ironarm (double weapon)
Kyousanken (double weapon)
Shadowdancer(two handed)
Doomsinger (two handed)
Kairishi (two handed)
yeah, doomsinger is supposed to be a two handed weapon stance that you powerstrike in. I tried it, never had much use for it but it was only 75% maybe, I don't think I ever got better at it.
Bladelore stances:
Bladestorm (double weapon)
Ironarm (double weapon)
Kyousanken (double weapon)
Shadowdancer(two handed)
Doomsinger (two handed)
Kairishi (two handed)
And thats exactly why I wouldnt even try using two weapons.
Quite misleading if thats the ase...
Well, I'm just going off the helps.
It may be otherwise.
I so just went into the stance and drew my dual weapons and tried, still a no go 
No doomsinger or no powerstrike?
And remember, powerstrike is automatic. It just happens when it happens.
It didn't seem to make a diffrance, like how bladestorm wont let me use a poelarm like a windmill
On another note if you will recall Divine mandates discussion of selectable skills is one of the bad mojo subjects.
Hrm...
DOOMSINGER
Syntax: cast 'doomsinger'
A ritualistic stance meant to be used with two handed weapon. While
under its effects the blademaster further extends the principles of
powerstrike, moving and attacking in harmony with the weapon's natural
frequency. In moments the blade begins to vibrate emitting a unique
high pitched tone as it sings with its own strength.
See also: HELP BLADELORE
Perhaps it was meant literally as a ritualistic stance, with no use in real combat. Perhaps for training anatomies or whatnot? I'm probably wrong, but seeing how you've used all sorts of weapons with the skill mastered... Also, from reading the file I always thought having a higher weight on the weapon would cause more damage. Then again, I never took a blademaster past level 30 so I wouldn't know for sure.
Every stance is a "ritualistic" stance.
On another note if you will recall Divine mandates discussion of selectable skills is one of the bad mojo subjects.
That did cross my mind, but since blademasters are open to everyone, and they do get all of their selects it didn't seem it should matter.
You mentioned a skill from a qclass only.
- With the exception of quest race' date=' quest class, cabal skills, mana charge, malform weapon, Tattoos (any) [b']and selectable skills, all skills may be speculated about. This means if you know, please don't spoil other's fun.
Please read the rules.
Some help files are only viewable by the class that can access them, UB.