Can you Twisp off-turn?
No. You don't play PVP Defense cards, you use abilities on those cards. Twisp doesn't mention copying PvP Defense abilities. This is supported by the fact that play is only used in reference to a player's own turn. From the correct Rulebook.

PVP ATTACKS AND DEFENSES - Some cards allow you to make a PvP Attack against the other players in the game. When you play a card with a PvP Attack ability, each other player has an opportunity to block the attack with a card that has a PvP Defense ability. A player using a PvP Defense card’s ability negates the attack only for that defending player.
Twisp: Catsby’s special card Twisp simply copies all abilities of any other card played in a turn, including Tokens, Power, card drawing, and PvP Attacks. If the card would be deleted, then Twisp is deleted.
Baby Ninja - {2}, +1 Power, PVP Defense: Discard this card to block a PVP Attack. If you do, draw a card.
Jim Darkmagic: Jim’s special hero power must be used before you take any actions or play any cards for your turn.