The power I would wish for is imposed empathy.
How it would work is as a person I can take my experiences or other peoples experiences and then dump those experiences on someone else who he is dismissive of those experiences until the point is made. There are no range limitations. I just have to simply know who is the target. I would also take the added extra that it is a power I can pass on to others and they, in turn, can also pass it on to others.
So, for instance, I meet a person in chronic pain. They tell me about it and how their doctor won't prescribe them enough pain relief because they think the person is abusing it. I would dump that experience on the doctor, the feeling of being dismissed, the pain it took to even get there in the first fucking place. The feeling of barely being able to think straight because of the pain even though you have followed the regimen and it is still not enough! They would get to know what it was like for a while, walking a mile in the person's shoes, disrupting their capacity to work as they too can no longer concentrate enough to read.
I would gift it to anyone who is being bullied mercilessly. So they can dump all their pain and hurt on the bully, every night spent crying at horrible things said or done being lived out. All the fear and misery they provoke. They get to live it as you have lived it till it fades and the point is made.
I would give it to people in terrible states of life, like with locked-in syndrome or similar who have no ability to end their life themselves without getting courts involved. They then can inflict the experience of their miserable state on those that would deny them this right. Dumping the experience of what bed sores needing to be packed feel like, and the sensation of every invasive medical procedure. Or the indignity of lying in their own faeces unable to alert anyone as their carers are no longer awake, as caked on shit goes hard and becomes its own discomfort.
It would be the closest thing approaching justice for the abused, who have had their minds damaged, self will shredded and go on suffering long after the fact. They can now dump it all on their abuser. Who is likely still swanning around untouched by justice. Because justice as a concept seems to only exists in Disney films from what I have seen... Giving them a full awful taste of everything. So they can truly know what they have done and just how deep it hurts!
The dispossessed soldiers sent to war on spurious lies, abandoned to the street ravaged by PTSD get to inflict this neglect on those who sent them in the first place and deny them access to dignity. Have them live out the theaters of war themselves, all the fear and blood. So next time they come to tick boxes to send people to a war they might not put their own self-interests first.
The potential is huge, especially as it is gifted to others and they, in turn, pass it on. I can dream… It was a fun thought experiment.