Cathar's Companion: good in limited
"Anime breaks through with the Hollywood-sponsored debuts of Pokmon and Princess Mononoke"
You also need the less glamorous answer: Charizard ex is a Stage 2, Crimson Storm discards two Fire Energy, and a list that cannot recover after the first attack is only a one-shot showcase
The deck has a modest set of point interactions, between removals and counterspells (Imprisoned in the Moon, Hanged Executioner, Arcane Denial, Crush Contraband, Swords to Plowshares and Darksteel Mutation) plus three sweepers, (Fell the Mighty, Flood of Tears, Kirtar's Wrath)
The change in power level between four and five drops may not be the steepest change but it is one of the more significant ones as it falls within the realms of the cards you can include without ruining your curve or consistency