Board Thread:Questions and Answers/@comment-5602817-20140424023046/@comment-11764949-20140425034208

If the omnitrix works in the way it seems, the changing animations are for the sake of the viewers. It seems it turns Ben into energy and reconfigures him on a cellular level. If it was merely swapping out his DNA, one, he would need to be alot younger for his body to accept the cahnge, and two, the pain would be excruciating. After his first transformation into Heatblast, he didn't even notice a change until he realized he was on fire.