there is one shapeshifter(other then the dragons) in the game.its a certain dwarven skeleton called mordus or something.he turns into something called a White Death(at least thats what the concept art for it is the creature is called something else in game)that might be a mind control based master form.then there is the lamenting abomination(also known as the werewolf)that could be a master strength form.although keep in mind that these creatures are related to the voidwoken somewhat.
aside from that I would love to see some voidwoken forms like the bat and deep ones.(I wouldnt lock the bat or deep one behind quests but I would lock the werewolf and white death behind there respective quests as well as giving them higher skill requirements to prevent them being used straight away as both the mordus fight and the werewolf fight are in act 2)

I hope I'm not sounding demanding or rude as these are just suggestions.I can come across as rude sometimes when I don't mean too :(

This is a cool idea, I'll look into it!

got another idea for a master form:Demon Lord using necrofire skills and the Adramahlihk model.uses 1 source point and has various skills requiring more source to use like epidemic of fire and other related necrofire skills.
another idea would be a form costing 3 source points thats the Source Titan at the end of the Nameless isle story.no clue what to use as skills.

the white death form/Mordus'Akim idea I had would be about mind control with a single target mindcontrol that can maybe penetrate armor(probaly too op)?along with some telepotation/battlefield control style of skills, the mordus hammer skill(its pretty much a renamed battle stomp skill already in the game that the boss uses) and maybe a mind control aoe (that is resisted by magic armor).

Why can't some forms use skills like Demon is still holding my weapon why can't I use warfare?

for balance reasons probably.

Is it just me or do the master forms feel underwhelming? I prefer my other forms over them to be honest.

Just wondering if the -30 is needed for silencing the character? I feel that it limits the build a lot - for instance, I can't benefit from necomancer's heal for damage or warfares bonuses to physical damage.
Is there a way to silence without taking away these abilities?

My limited testing puts the current balance pretty good, if not a bit behind traditional 'roles' (i.e. my generic knight with only base game skills survives as much and has more variety of skills and debuffs/damage than a troll or bear). But, the knight also can't be a water elemental, so I understand silencing abilities that are outside polymorphing, just hoped it could be completed differently - like the enrage skill.

@ Surrealialis The -30 is used as a replacement for "Atrophy." The engine allows for me to have skills ignore silence, but not atrophy, so I had to find a way around that. I understand its a bit clunky, and it's why I'm hoping that it will be one of the new functionalities added to the engine in the "big update" coming soon.