Vax has explained that if someone travels a few seconds into the past in the Time Distorter, he or she cannot change their mind. This scenario could cause several side-effects. The Time Distorter can reverse their age if they are not careful.
Vax has figured out that he is not effected by this, but can become younger if the Time Distorter touches the Time Field when in the Time Vortex. If someone were to alter the past to where someone was never born, they would no longer have a reason to alter the past, resulting in a continuous cycle which would break the Universe.
Time travel is filled with paradoxes, and if someone were to travel to the beginning of time, they would have to stand still for 6 days. If they did not stand still, it would cause time and space to rupture and end. The fabric of time would completely disintegrate, ending the Universe, as there was no real time back then, since time had not officially started. Altering the past in a certain way can alter someone's brain waves to where they do not remember a single thing. Their brain would be completely drained, and would just be a hollow shell of Atoms.