Guys, I have a question:
There's something which stops well CHALK and another one that stops Perish Trap?
For CHALK I heard M-Swamper is a good choice but I don't want play a Rain team everytime.
If you want to be technical, absolutely nothing stops Perish Trap unless you're running a mono Ghost team, VoltTurn team (even then its not perfect thanks to Protect + Disable), or six Soundproof mons, and considering that Bouffalant and Electrode are the only remotely viable choices that's not a good idea either. It's called Perish Cancer because you're pretty much fucked no matter what you do, like real cancer. Soundproof Electrode outspeeds Mega Gengar, and Taunt shuts it down. Max Speed Whimsicott's Taunt is unmatched, but Whimsicott is a common partner to Mega Gengar for this reason and its priority Encore.
CHALK, I fail to see how Mega Swampy does anything to stop Cresselia laughing, using Trick Room, then letting its teammates pummel it to death. And Amoonguss gives no fuck. Put Cress + Amoonguss and you just lost your mega.
Primal Groudon is just about the only thing I can think of that would *singlehandedly* demolish all of them, but its obviously banned in VGC15. If there was one thing that could beat all 5 we'd all be running that and CHALK would be dead in a month or two.
Bulky water stops Landog and Heatran, Taunt stops Amoonguss / Cress, Khan... only really fears Burn, Intimidate (to an extent), and faster Fighting mons (Terrakion/Virizion/Mienshao/Infernape/Blaziken) though Ghosts work as well if it lacks Crunch (Gengar and Aegislash are the usual choice).
LO Infernape / Blaziken can smash Heatran, Amoonguss, Khan, and Landog (HP Ice) but need help on Landog and Cress, that's about as close as you get in one slot. You need a core that stops the 5 of them, not one mon; if such a thing exists it would simply snap under the pressure of doing so.
Also with CHALK, imo, Thundurus is pretty much as prevalent and pops into mind when I think of them so pack a hard hitting Rock / Ice move or Lightningrod for that.