it all depends. for your aunt's case, it is because her son is
young and does not and do not know what is to be learnt and what is
not. Afterall power rangers is a every-episode-fight-win show,
which makes the son pretty much want to learn the moves, since he
knows that power rangers are the ''good'' guys.
my cousin watched power rangers, and yes, he started kicking around
and stuff..but im sure as he grows older he'll stop'em . i remember
when i was young and watching power rangers, i myself too do a
little kick and stuff, it's just like influence and stuff...example
after watching some harry potter movie u start taking some stick
pointing at your friends and chanting the spell(for some.)
Overall what i want to say is, it does not make u violent, except
if u're a kid ( like below 7 years old? ) other than that..how the
show influenecs you is depended on how you think..