Fanfiction help

[Xombie122]

So I'm thinking of trying to get back into writing fanfiction (my previous stuff is all on fanfiction.net) by doing a CYOA using Lt Ouroumov's Worm CYOA v17 but there's a bit in the descriptions of one of the powers I'd like a second opinion on in the description it says: 'You can choose to be fully transformed into a Tarrasque, have a hybrid form between the Tarrasque and your current form or simply wield its power in whatever form you may have.' initially to me it seemed like it meant that if you had that power you could change forms from a human to a Tarrasque or a human/Tarrasque hybrid when ever you liked but after thinking about it some more I kind of think that it might mean that I have to chose one of those forms and that will be what the character looks like for the rest of the fic. I like the idea of fighting lung and when he's full rage dragon and going "Ok lung I see your dragon and raise you a Tarrasque" then turning in a Tarrasque but I can see that being able to do so might make some parts of the story boring like a fight against the slaughterhouse 9 being in Tarrasque form then using it's ability to eat and digest everything Bonesaw? pick her up and swallow her all hose plagues and diseases she's trapped her body with to release in the event of her death? delicious, Crawler? mmm, crunchy the Siberian? would just phase or carve her way out sure but I don't think she can actually do the correct damage to kill a Tarrasque temporarily let alone permanently