Niko would easily fit well in a deck based around Constellation mechanic. Probably go Bant colors GUW as that gives access to Nessian Wanderer and Setessan Champion. While Archon of Sun's Grace helps with field presence.
Looking over the dragons, instant speed Knollspine Dragon from the deck to load the hand. In something like EDH this would benefit from opponents beating each other up.
I say change werewolf to wolf you know maro and the gang would not put werewolf's in not Innistrad besides we're going back there after D&D set and it's more regular wolve's than werewolf particularly fenrir
I think Lycanthrope using just the "Were" should be a separate creature typing. So we have a general Lycanthrope tribal. Werewolf would be Were Wolf.
Niko would easily fit well in a deck based around Constellation mechanic. Probably go Bant colors GUW as that gives access to Nessian Wanderer and Setessan Champion. While Archon of Sun's Grace helps with field presence.
Skyline Despot is also not bad if needing monarch.
Also being able to reuse Yawgmoth's Vile Offering as often as you want.
I think Lycanthrope using just the "Were" should be a separate creature typing. So we have a general Lycanthrope tribal. Werewolf would be Were Wolf.
Spirit Warrior creature typing for Einherjar.
Valkyries will be Angels like Adarkar Valkyrie. They could probably have additional class type like Warrior.
I think Chroma could return as their version of Devotion. Each of the Gods in the set has a Chroma ability like one being a Light from Within.