original series pokemon cards The 150 Pokémon Trading Card Game (1999 editions) - post Pokemon TCG Base Set Checklist:

All of these are instants that target a creature and let us draw a card

You add just two counters on your blue planeswalker, because Doubling Season specifically says you only get double counters from an effect , and adding loyalty counters to activate a loyalty ability is a cost , not an effect

Transforming cards to introduce werewolves into the game is peak design in my opinion

As for the question, if you have two in play, each one applies to any draw you would make (besides your normal draw for the turn)

And it has a secondary use, regardless of format: Rather than enchant other players, you can enchant yourself with this curse, and you'll get Gold whenever another player attacks you

Only a handful exist, making it one of the rarest Pokmon test print cards ever discovered