You are a traveler.
Your sibling is, too.
Together, you jump through worlds, with a power of unknown origin that you constantly inquired about (but stopped long ago). You meet people and see places and learn things. Every new world is rich with its own life and culture. They speak different languages (all of which you understand) and have different beliefs, putting faith in either God or gods, or none at all. Some greet with open arms, some are hostile, and some are ravaged beyond repair. Some don't even have a semblance of human impact. You've seen everything. You've seen beautiful sights of craters and waterfalls and mountains and hills and formations unlike any other. You've seen the most vile things mankind is capable of and the greatest. You've watched civilizations die and empires rise. Sometimes you're lucky enough to witness the collapse of a world.
Most of all, you are powerful.
You always wield power. Be it physical or mental or elemental or whichever that place relies on. It was one of the few blessings you've received from a higher power. Always with the room to adapt, sometimes, you are hailed as almighty.
But you can't remember your past. You talk to your sibling often— what other choice do you have?— and they don't, either. For as long as the either of you can recall, the two of you have been traveling acquaintances, visiting near and far. Your appearance has been the same for as long as you can think. Your clothes never seem to get stained. Your hair never lengthens and it only grows back if cut.
You can't die. You've tried.
Different locations have different measurements of time. You've been around for a long time, far longer than what others would say, likely since many places have been formed. Usually, you are treated as someone fairly young, upon arrival, so you presume that is the stage of life in which you are stuck in. You always look hard at the lines etched in the elders' faces and the minute stature of the children. You wonder if you were ever small like that, and you wonder if you will ever be as refined as that.
You debate within yourself. You don't know many things, despite having precise memory and a lifetime's worth of learning. You've seen so much and yet there's always more that can surprise you. You're torn between the want for death, for sleep at last, and the greedily taken extravagance of what life can offer. You wear masks and treat every living creature you meet with an ever shifting regard. You've tried taking on different identities every new meeting, from passive to mean to melancholic to snarky. But at your core, you don't know which one is you. You still make jokes with your sibling and laugh and cry with them. The emotions are sure in your heart, but you wonder if one day they might not be.
You worry about your sibling. At the end of everything, they're the only one that really stays, no matter how wondrous the populate could be. You can't afford to lose yourself in thought and feed the nightmares of losing them. You shove those anxieties to the back of your head, praying that it never happens.
You try not to wonder what you're living for, and you push on.