As one of the earlier expansions of the TCG, EX Dragon Frontiers is primarily represented through types from Generation III Pokmon
That said, the Pokemon Flute Item Card from the Mythical Island expansion pack can help curb this a little, forcing the opponent to take a Pokemon from their discard pile and put it on their bench
Cards like Impermanence are replaceable with budget picks such as Forbidden Chalice or Kaijus in the meantime, but ED pieces such as Drident or (the second) Shuraig are not
Thalia isnt more than $6 and shes better in more places, so I dont think Gryff can climb above that for awhile
Generally speaking if the Agenda gets to a resolution first, things are going to work out badly, and if the Act gets there first, the story will go in your favour
If you find yourself among grind-game decks, bumping up your Flute of Summoning Dragon count and supplementing the deck with additional Tyrant Dragons is an easy way to do an impression of an aggro deck