That's definitely interesting. I'm not sure how to fit that into my existing theory of How Things Work, which means there's got to be a big hole in it somewhere. I can kind of explain how general shapeshifting might work (a spirit that's poured his whole fade-water-self into a physical cup, so to speak. Like Cole. Assuming he gained enough Will to exert mental control over the cup’s shape, then he really could change into anything he liked.) Being limited to two forms, though... hmm. And I still don't really get why Cole bleeds. He's manifested some degree of Will, yes- and getting stronger all the time- but his Song should still be so weak compared to everyone else...
And for the Lady to have Will strong enough to actually force change on existing physical reality with a few drops of blood? Yikes. That's really strong. Incredibly old, maybe even partially dragon-level strong. Some kind of direct connection to Mythal would make sense, I suppose, given her domain....
Ugh. More questions than answers. I should play the game.
About the Cole bleeding thing, I questioned that too. He doesn't eat, presumably doesn't relieve himself, Solas (not really, he just asked if Cole was interested in women) and Bull seem to believe he can [insert one of Isabela's colorful variety of ways to say having sex], and does he sleep (doesn't look like it)? So why then, does he bleed?
Have you not played Origins madrar? Or are you just talking about getting back to playing Inquisition?