I hope you are having a marvelously fun day today
Without it, Miraidon ex is a good card, but it would have to be played alongside Flaaffy, which would be slow and require Bench space (which means fewer Regieleki VMAX in play)
Additionally, there will be an updated version of the Pokmon ex cards which differs from the ones in Black and White and XY by including Pokmon that are Basic, Stage 1, or Stage 2 rather than all Basic
Modern Horizons Sets: Premium Power and Price Considerations Modern Horizons 2 and Modern Horizons 3 introduced powerful new cards and Set Boosters as a premium product option
Plasma Freeze is one of a trio of sets themed after the generation's villains, Team Plasma
Legality depends on the tournament format -- Origin Forme Palkia VSTAR ASR 40 can be legal in some formats and banned or restricted in others