Most of the people would think that changing the past is more efficient than seeing the future. If you think for some time Actually you can change the past by seeing the future. so this is how it works for example:you go to the future and see that you got caught by a really deadly Diases and you just search for the main source of the Diases and find out the day that you got caught by that diases and you can just figure out a way by not doing the think which caused the diases.
But that is actually my opinion some people may think changing the past is a better superpower.Actually to be honest i also think that in some ways it is better to have the changing the past power because it is useful some times. You may be embrassed for some reason and you regret the thing that you made before,So it is usefull in situations like this.But seeing the future also helps you to jump from the obstacles that are coming towards you because you can prepare before it comes, you will even be ready before it hitts you.
But if i had the ability of seeing the future i wouldnt wait for a single minute.I would check my future and depanding on it i would shape it with trying something different and checking the future again and again untill it becomes perfect.So this is the thing that makes people to think more,the common thing between them is both of the Powers can change the future in different ways.As ı said in seeing the future power you can just shape your future acting according to the thing that you see with your power.But in changing the past power it is a bit harder because if u havent done something big that will effect your future the power just doesnt make a big effect on you but for example if you had 1 wrong on IGCSE and you missed Oxford for only 1 wrong mark you can just go back to the future and do it correctly. So this is my opinion on the Powers ı would still choose the seeing the future one but actually it doesn’t mean changing the past is a bad ability to have.