It really depends what your tricker is and what your two set up sweepers are. After a Charm or Memento, Drapion can set up on X-scissor fine and I'm pretty sure Megahorn also. Registeel can take Megahorns fine as well, just keep cursing. Metagross Meteor Mash is always a problem and yeah, you have to make your team to plan for that.
The point of trick-scarfing is to provide for locked down moves that your set up sweepers can set up on, and usually this is done by some sort of Levitating/Flying Dragon + Steel combo (since between those 2 almost every type is resisted), or the trick-scarfer itself can be a Dragon (e.g. Latias) or Steel (Metagross, not as common) to make that combo. Alternatively, Drapion's a bit different in that it has the special ability Shell Armor - preventing critical hits, and it has good neutral typing with only ONE weakness. And obviously it also has fairly decent bulk, and together with Acupressure for boosting all stats including accuracy and evasion, that's quite the ideal non-haxxable pokemon to use after it's fully set up. After opponent gets a Memento, Drapion can set up on basically ANY neutral move and even unSTAB earthquakes and earth powers (and even some STAB ones) --> As long as it takes less than 37.5% from any hit it is not 3HKO'd by anything (with leftovers/black sludge), so it can use rest to stall out whatever move it is. With Charm (instead of Memento) Drapion might have a slightly harder time on the special side, but it can still take on (and set up on) a lot of neutral moves that aren't too powerful, especially after a thunderwave and potentially some flashes.
Flare Blitz I think wouldn't be too big of a problem for Drapion if I remember things correctly when I tried using an Uxie + Drapion combo some time ago (as long as Uxie isn't 2HKO'd by Flare Blitz, it can Trick, Twave, Memento, and things are fine). I believe Mesprit has a small chance to be 2HKO'd by Arcanine Flare Blitz. If you have an Intimidator like Gyarados or Salamence, then that's probably also fine as well (after Intimidate Gyarados/Salamence should be able to set up with their resistance and decent bulk). Garchomp is "not as good" at taking Flare Blitz... I dunno if you are using him or not... If you are using Jumpman's team exactly (I dunno... maybe you totally aren't haha), then Drapion should be able to set up fine (Drapion takes like 23% max from Flare Blitz after Memento).
Meteor Mash is really annoying if it gets a few Attack boosts... I dunno if there's really much that can be done about it unless you can make it such that the Metagross with Meteor Mash will be locked into something else instead of Meteor mash (Trick Scarf Starmie, Metagross, or lol Switcheroo Arbok can do that, though none of those are that common, but I mean, obviously you gain some, you lose some, depending on what trick scarf lead you use). Registeel can set up on Metagross Meteor Mashes decently too as long as Metagross doesn't get like 4 attack boosts or untimely crits or something.
EDIT: Oh! I realize... maybe you're using Cresselia. That's what Reflect is there for. Trick, Twave, Reflect, and if still alive then flash until you're dead... or just flash if it's Megahorn... I dunno actually, it might not be the best to do this since Heracross might have guts boost from Twave. That's why Mesprit with Charm might be better. It can just charm right off the bat without tricking since you know all Heracrosses are physical while with Cress... it's hard to say.