Yes I skipped all the fluff bullshit for you. This rant brought to you by the YouTube algorhythm. Which somehow thought I'd want to see the moron answer to this stupid question.
Idiot Question (summary, not word-for-word): How would you create an early encounter with the villain of the campaign and stop the characters from trying to kill the villain and instead run away?
Video Person Answer (summary, not word-for-word): Have his reputation proceed him with rumors, agents, etc cropping up along the way long before the PCs even know who he is and where he's at. Make them go through lieutenants, video-game style because RPGs are the best medium to act like video games. That never fails.
After meandering for a while on this, Video Person starts ranting about agency. His own solution also fucks agency up the ass, it just is slightly better at hiding it as you still can't go fight this billy bad ass until the GM thinks you're ready for it/the list of lieutenants is entirely crossed off. This is why I call him a moron.
Correct Answer: You're thinking about D&D wrong entirely, both of you. Instead of the stupid small dick hairless-nads twelve-year-old simpleton way of thinking about D&D where it's a linear video game or linear book story where the GM sets up set pieces for the PCs to wander through like idiots acting in a play they don't quite know the end of, maybe actually RUN A GODDAMN WORLD with it.
The answer is you're dumb at onset if you're building a villain who isn't merely a character with motivations, goals, power, a faction they support/own, a faction they oppose, and obstacles that circumvent that power from attaining those goals immediately, possibly the obstacle being one of his involved factions. This guy doesn't have to be classically evil, and probably shouldn't be because D&D isn't Zelda. Then make 20 of these people. Make some of their obstacles be other people on the same list. Congratulations, you have the very early beginnings of a campaign with agency now. Throw away your grand plots, keep it simple stupid. Grand plots are for novelists and current-day TV show writers. Let the players decide who the bad guys are. That's agency, retards
Only limp-dick lame-brain 5E players who piss and moan about agency without actually knowing what that is think this question isn't moronic and this answer EVEN MORE MORONIC.