Adapt to the world initially, find a stable point, assess plausible long term goals.
If I’m given a briefing and allowed to choose my power? Plant growth and control. At baseline this will let me farm super effectively, which would be incredibly useful in a world with consistent food shortages. Depending on how generous with cheats this mysterious entity is I might get a lot more. If I’m very lucky this is a world where magical plant monsters exist, at which point I could make myself a small army. If I don’t get something this flexible or constructive, I’ll need to make do. I will in any case assume I’m sufficiently OP that I’m automatically noteworthy, because the question presupposes that I’m in a state to be casting judgement upon the unworthy.
Find the least shitty warlord available and offer my services. He will be evil (best I can hope for in this world is pragmatic), but if he is willing to play ball then I’m open to using him and being used in return. I feed his army/quickly grow fortifications/ create an army of DnD twig blight fodder/ whatever, and in return he agrees to some basic reforms in the lands he rules.
All things that will help him in the long term. Things I can justify.
Take in orphans and raise them to be loyal to him, fed and trained as servants and eventually warriors. I’m basing this off of Janissaries, who were pretty nifty until they took over. Frankly, if I can influence their education then them eventually taking over is fine by me.
Enforce discipline among his soldiers, curbing and punishing at least some of the world excesses of war. Our people are commodities, and they must be cultivated. Evil is everywhere; you don’t need to do much to be seen as the better deal by even a cynic.
Reward the competent and loyal, brutally destroy the incompetent and treacherous. Lying or misconstruing the truth to your superiors is a greater crime than any failure, and the punishments will make me sick. Brutality is the only language these people speak, so I guess I’ll need to become fluent in it. Honest failures are exiled at worst; those who hide their sins are broken on the rack
Fund artists, philosophers, and poets and add them to his court. Foster some small level of culture focused on duty and order, if not morality.
Bring in scholars, focused upon history, tactics, engineering, and magic. Create a university for the most intelligent in his lands to attend, and weave ethics into their education so that it’s the affluent, educated, trendy high class thing to at least PRETEND to be a decent person. Some will slip up and actually turn out decent.
In short, back someone pragmatic and convince him of the value of ethics. Not morals, those will fall by the wayside quickly. No, ethics that work. Ethics that make him strong and let him build something worth having for his children.
Make the seed of something better, cultivate it, and protect it until I die. Realistically, even this will likely fail, but if I can swing it, it’ll allow me to live a life of *relative* comfort and influence while introducing the shade of charcoal grey to a tapestry of black. It won’t clash as much as a slash of pink, so maybe it will last long enough to become something even lighter with age.
If the world is really as shit as you say, anything is an improvement. I’ll take that justification and run with it, but if my plan works I’ll end up as the Merlin of this world. Doing things that range from sketchy to incredibly fucked up in order to create a baseline functional society that might only last a generation or two, but will hopefully create a legacy that eventually ends slavery as a byproduct of empire and moral grandstanding.
