Legality depends on the tournament format -- Yuna, Hope of Spira can be legal in some formats and banned or restricted in others
I think Shock is fine because it is the basic market rate for a burn spell
Avenger of Zendikar brings an army of tokens with it, especially if youve done a lot of land ramping with Cultivate effects, and it fits alongside another common Naya payoff: token doublers like Elspeth, Storm Slayer
Thankfully, they also make it so that when they enter the battlefield, each token that would be created under an opponents control this turn is created under your control instead
Introduction of Skypeia and Revolutionary Army Characters As mentioned above, Protagonist of the New Generation will feature popular characters from Skypeia and the Revolutionary Army
It's no Volrath's Stronghold