well, i`d would like to see some kind of invulnabitily, cause its in the show,
watch goku vs. cap. ginyu, goku starts powering up, and when he became stronger than ginyu, he couldnt be hurt by the ki attacks ginyu shot at him.
second example, the trans from semi perfect cell to perfect cell,
trunks attacked him full strenght but it didnt had any effect,
i dont know if this could be coded in, but:
what if it were so that the person transforming, creates a power shield around him, that would block attacks, but then in the way like it was super vegetto vs super buu, the shield can be broken but with an power struggle of some kind
nice idea?