Only Obelisk has protection from enemy cards and effects, and it can still be destroyed by effects that don't declare a target
As a starter Pokemon this card wouldn't be useful because it can't attack for three turns, at least do damage that is, and if you use Nap each turn until you get three energy cards, doing 30 damage a turn with Razor Leaf won't do much against a stage 1 or a stage 2 Pokemon
The ability being dependent on the power of the cards just makes this scalable, and Im sure there is an infinite attack combo in there somewhere that helps get around fog effects
But because historic permanents are so common, this card will likely end up being pretty cheap to play
Each Draft Booster contains 15 cards and 1 token/ad card or Helper card, including 1 card of rarity Rare or higher and 3 Uncommons, 10 Commons, and 1 Land cards
Because it's an alternate cost as well, and only from the hand, it's fairly limiting in terms of combo potential outside of a few fringe examples that are 1-mana versions of effects we already see as outlets (or in the case of Weftstalker Ardent, enablers with a hack to Pirate)