Those look terrific! I think the unicorn on the chest looks great.
One suggestion I'd have is maybe to lighten the unicorn crest on the helmet a bit - just with strokes of thin white on the obvious highlights, like the brows, the crests of the nostrils and the tops of the ears. It looks good as it stands, but it's possibly a little duller than the unicorn on the surcoat. I think a few strokes of white would bring it up to the same level of brightness.
Anyway, great work - I love that harlequin surcoat!