I hate game effects like this, especially as there's no game effect to modify printed costs. If it was based on odd (total) strengths that might have been more acceptable, but right now this is an effect whose strength is almost entirely at the whims of fate, and thus makes the game a slightly more-random and less-skillful experience.

I don't think that this card makes the game more random, given that I don't think that this card will see much play (unless we see cost manipulation).

Because you can't manipulate cost, its effectiveness is basically determined by the dynasty flip. Realistically, nobody is going to alter their decks cost curve in light of this card, so its effectiveness is basically a lucky dip. If you're opponent draws just even-costed dynasty characters, he becomes unblockable for a turn. If not, then he's poor for cost.

That depends, it could be that their only odd coster happens to be a card they don't want to play out this turn, or that they want to attack with (eg Lion's Pride Brawler). 

Short term not a good card, long term decks based on cost could be a thing. They were in Invasion for Orcs and Goblins. Also a green faction. 

Weird and unreliable!

I'm with Asklepious but I dont think it will be so impactfull since 5 is odd.