I made this shape using object blend in Illustrator, now I would like to use this shape in After Effects or replicate it to be able to see the shape "grow". I want the gradient to go from start point to and point of the shape and not of the screen, when I was trying if the shape would go backwards instead of being darker it would go lighter again.
AE has no blends. You have to import your pre-existing graphic and mask it out using a stroke on a path and similar techniques.
you can try using this technique if all you want is for the shape to go from start to end and complete to full
you expand the blend and use the layers in sequence to reveal one after the other. then you stretch all the layers.