I'm going to be starting a campaign next week with 5 or 6 players, and so far there's a strong push from at least two of them to go all-out and start the game at Submerged level with lots of supernatural interference. (10 refresh, with wizards with white council status, knights of the cross equivalents, plenty of deity interference, etc; I'm not sure we're likely to have any true mortals at all.) I ran a quick one-shot for them before we really got started, since we had a day with a missing player, and discovered that it is *hard* to create good, challenging opposition for a large, high-powered party.
I'm not a sufficiently experienced and fast-thinking GM to run more than two (*maybe* three) simultaneous interesting NPCs; that means that a pack of Denariians are right out unless I recruit an NPC assistant for some special mega-battle. That leaves me trying to cram some 50-70 points of powers into two or three NPCs. I'm seriously concerned about the NPCs starting to look all the same after a while, because there just aren't *that* many powers in the book; if I give everything supernatural toughness and recovery, and their mental or social equivalents, and I'm *still* looking at full-PC power numbers. I'm really worried that my big NPCs will end up varying only slightly in their mechanical effects. I tried throwing in a bunch of low-power minions, which was interesting for an encounter, but not really something that seems to work well for major opposition and prone to slowing the game down.
Experienced GMs: How do you provide interesting, runnable opposition for a high-powered party over a long campaign? I'm trying to figure out whether I'll need to tell the players that we need to tone the power level down, but I would really prefer not to, given how excited they seem to be about the high-powered game.