If that creature is no longer on the battlefield, use its toughness as it last existed on the battlefield to determine how much life to gain
losing a V Pokmon can mean losing a game quite quickly
On the other hand, Turtle Power has a whopping 15 multicolor lands which enter untapped (if you count Fabled Passage, which can fetch any color), and it has some bloody good ones for that matter
And while she has some positive aspects (the phenomenal ward ability and two lore value), ultimately she probably wont see a ton of play given there are better options out there for granting extra strength
Much like Bartolom del PresidioBartolom del Presidio, Umbral Collar ZealotUmbral Collar Zealot allows you to sacrifice creatures and artifacts, but unlike Seor Bart, the Zealot has a stronger payoff and can go into more decks thanks to it being only one color