Alright, final submission.
Unfortunately, it turns out that Anim Transfer only transfers bones with a 'common' name, such as "Bone_Root" and whatnot, and will not transfer things called "Mesh03" and "Bone_Eyebrow" and whatnot. I managed to transfer the animations to the regular model, but not to the portrait; Therefore, the only way to get the alternate portrait to display in-game properly is to import the model twice, naming the first one something like "SylvanSentinel(_Portrait).mdx" and the second one "SylvanSentinel_Barkskin(_Portrait).mdx". I hope the judges will take this into consideration.
Also, the model doesn't display properly in Magos(spell effects and the glow on the back), and saving in Magos after viewing an animation actually breaks it, so I suggest(and request) to test the model in-game.
"The Sylvan Sentinels are Night Elves who are proficient at both the art of warfare as well as the art of druidism. These stalwart protectors of the wilds are capable of calling upon the spirits of the forest to assist them in a time of need, and are in fact so attuned with the forest that they have given up some of their mortal body and spirit to become closer to the wilds that they inhabit. They are also capable of becoming one with nature - turning their skin into tough bark, and channeling the power of the wilds to assist them in combat."
Suggested soundset is "Dryad", suggested base is Sylvanas Windrunner. Missile included. Will make an extra spell model for the Arrow Barrage skill later. Recommended druid Morph or similar ability to test Barkskin effect.