TL:DR : Competing with 3 rune cards, not a win condition, wings are strong but she herself is weak, Rainbow DK has little win conditions, would fit best in Unholy Token, but is Frost-Blood rune not Frost-Unholy.
Full Post:
So to start, there are many great aspects of the new mini set colossus, and I wouldn’t say she is the worst one in the game, however, I find her issues lie more in her role of the DK deck plan with runes. Since she is built for “rainbow” or split frost blood decks, unlike every other colossus, she is competing for a deck build rather then a spot on the team. Many other colossuses are either win conditions all together, or a frightening threat to leave alone for too long.
Since she forces split deck play she is fighting against 3 rune cards like Vampiric Blood+Soul Stealer, Frostworm’s Fury+Lady Deathwhisper, and Grave Strength+Lord Marrowgar. It is worth mentioning too that she is Frost+Blood and not Frost+Unholy. She seems like she would fit well into a unholy style of play where you build token. She can be a mid game emergency clear and can have some safty behind a Anti-Magic-Shell to try and force minion trade.
As she stands, she is basically a meh board clear, that requires additional cards (of which there aren’t many) to freeze to clear board. To which I say, why not just double down for triple blood and get the far superior Souleater for 1 more mana, and a FULL board clear along with the other percs of 3 blood.
Possible improvements?
The main ideas I had were in some way to make her last more then 1 turn, or give instant value. Either give her character freeze/rush so she can help clear, or give her wings or her a deathrattle of “spawn a frozen champion on death” like her original. That way she has more game presence even after death. Alternatively, you could give her wings a deathrattle “Add a Icy Touch to your hand that cost (1) more mana this turn” this would give you an additional instant clear, and some return value like most other colossus have. Last Idea is maker her a 9 or 10 cost like other dragons, remove rush on wings, and just have her freeze the whole board (both sides) on being placed, like Frostworm’s fury, without the damage.
I hope she gets buffed atleast a little as she is a cool concept, but seem just rather weak in the DK design until more cards roll out. Hopefully she gets some love, or if not, some much more “Win condition” cards roll out quick for rainbow DK cause it definitly is in a weaker spot it feels, expecially against Pure Spell decks.