There is often the temptation for GMs to make enemies powerful. After all, good conflict equals a strong story and a strong story holds interest. Most players (and especially GMs) would quickly tire if there were no challenges in the story and everything could be click-whirred it's way to easy victory. On the other hand, having *no* easy challenges means that the players can never feel powerful and impressive and, let's face it, most players are in the game for a bit of wish fulfilment.
Now most GMs know a pretty easy balance to strike with this. You include some mooks and you have a big bad, every single time. The trouble with this option is that it's simplistic and can be dull in its own right. Now clearly it works well for action-oriented dungeon crawls but if you consider games like the World of Darkness where combat is rarer and with fewer numbers, the temptation to create powerful antagonists is high.
What we need to do is arrest that assumption.
Sometimes you don't need a powerful villain. Sometimes a pathetic one is even better.
Let's say you have a group of highly powerful vampires, a few elders even, and they get dropped into a section of the Spirit World. The obvious option is to have some badass spirits smack them down. But you could look at it a little deeper. One is the Prince. One has a ritual that gives him honorary Spirit Rank. One is the guy whose Alter-Ego did a great job of breaking everything and is now the Atoner.
Rather than having the spirits beat face and throw down, you could instead build up the creep factor. Show everything off-kilter. Reveal the spirits as both clear and unclear entities where one can't be sure where the architecture ends and the spirits begin. Threaten them with spooky glimpses of nasty looking spirits. And then during the first major confrontation, have the spirit cower before the Atoner, have it bow and scrape to the elders.
When they make their way to the Big Bad and the Elder buffs for all he's worth to tear the Bad Spirit apart, let it discorporate and have the other spirits cast Numina that banishes them back to their own reality. Why?
Because the most interesting outcomes for such powerful PCs is What They Choose To Do. Do they take the peaceful option? Do they let their successes run to their head and jump out at a truly scary creature on the main road? Also how does it feel as an Atoner to have the monsters fear you? Do they attempt to forge the area into their own Dominion and what would be the ramifications of that?
In the end, the character's decisions are key.
Let them decide and see what happens.