Nope, Milkshape is not freeware but $25 may be acceptable...
Speaking of the ghost helmet

, you remind me of that. I'll see what I can do. But very unfortunately, it is the only tiny bug of the convertor that when importing Chivalric Knights' mesh there will be something wrong and it's easy but a little troublesome to solve it. Chivalric Knight is the very unit that has the ghost helmet
Sorry for the mistake

And thank you for telling me the author. I can't believe I just know this though I love this mod...