It becomes red if you do that, and the color identity bars it from some Commander decks that might want it, but overall this is just a quirky combination of two existing creatures
Not many non-combo decks can support card quality, even card quality with synergy, when it comes at a card advantage cost
(2022-12-08) "Flashback [cost]" means "You may cast this card from your graveyard by paying [cost] rather than paying its mana cost" and "If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack." (2021-03-19) You must still follow any timing restrictions and permissions, including those based on the card's type
You can do it efficiently, but youll have to give something up
It is just about the weakest creature in magic you can have and still live on a battlefield
From Assault Formation to High Alert, there are plenty of ways to get Walls moving