I love to study domestic cats ( the cat behaviour) but I have a question which always baffled me. If I have some sci-fi device which can make my cat big as lion ,is the cat going to attack me or eat me or something , or just will behave like always? I have to note that my cat is a little bit willd , she love to hunt birds and other small animals and she bring me "presents" at night.Also when it`s not happy (when i move her from her favourite place ) sometime she attack me. Some times behave like a willd cat :)
Thank you

Sorry, but there is no way to answer this with any confidence. You're asking how an animal will react to a sudden change in its own size -- something that never happens in real life, and so simply can't be analysed.

What we can say is that a house-cat the size of a lion would not be very well engineered: lions are proportionally more robust than house-cats, as they need to be to function with similar athleticism.