Does the final tribulation include both God's wrath and Satan's wrath?
Yes. Scripture describes the final three and a half years as a double-barreled outpouring: wrath from a righteous God and wrath from Satan and his forces. Satan, cast out of heaven with short time, unleashes all he can, while God's wrath also falls during that period.
Les teaches that the final three and a half years are the period of the wrath of God, but they are also marked by Satan's wrath. Satan is cast out of heaven, knows his time is short, and pulls out all the plugs, doing everything he can. So this is a double-barreled unloading on the planet: one hand from satanic forces, the other from a righteous God. Les says human beings cannot comprehend what that last three and a half years will be like. Even the horrible pictures from Yugoslavia, other areas, and the Holocaust together will not come close. Jesus Himself said in Matthew 24 that these will be days of great tribulation such as never were before, nor ever could be again. Thus the final outpouring includes not only the wrath of God but also the wrath of Satan.