"God manifests His power" during the seven last plagues. Evil men and angels tremble and fear for their lives. Why does Jesus punish them? Because they have transgressed the law! They fear the wrath of God.

Read the whole thing:

" For seven days after Noah and his family entered the ark, there appeared no sign of the coming storm. During this period their faith was tested. It was a time of triumph to the world without. The apparent delay confirmed them in the belief that Noah's message was a delusion, and that the Flood would never come. Notwithstanding the solemn scenes which they had witnessed--the beasts and birds entering the ark, and the angel of God closing the door--they still continued their sport and revelry, even making a jest of these signal manifestations of God's power. They gathered in crowds about the ark, deriding its inmates with a daring violence which they had never ventured upon before. {PP 98.3}
But upon the eighth day dark clouds overspread the heavens. There followed the muttering of thunder and the flash of lightning. Soon large drops of rain began to fall. The world had never witnessed anything like this, and the hearts of men were struck with fear. All were secretly inquiring, "Can it be that Noah was in the right, and that the world is doomed to destruction?" Darker and darker grew the heavens, and faster came the falling rain. The beasts were roaming about in the wildest terror, and their discordant cries seemed to moan out their own destiny and the fate of man. Then "the fountains of the great deep" were "broken up, and the windows of heaven were opened." Water appeared to come from the clouds in mighty cataracts. Rivers broke away from their boundaries, and overflowed the valleys. Jets of water burst from the earth with indescribable force, throwing massive rocks hundreds of feet into the air, and these, in falling, buried themselves deep in the ground. {PP 99.1}
The people first beheld the destruction of the works of their own hands. Their splendid buildings, and the beautiful gardens and groves where they had placed their idols, were destroyed by lightning from heaven, and the ruins were scattered far and wide. The altars on which human sacrifices had been offered were torn down, and the worshipers were made to tremble at the power of the living God, and to know that it was their corruption and idolatry which had called down their destruction. {PP 99.2}
As the violence of the storm increased, trees, buildings, rocks, and earth were hurled in every direction. The terror of man and beast was beyond description. Above the roar of the tempest was heard the wailing of a people that had despised the authority of God. Satan himself, who was compelled to remain in the midst of the warring elements, feared for his own existence. He had delighted to control so powerful a race, and desired them to live to practice their abominations and continue their rebellion against the Ruler of heaven. He now uttered imprecations against God,
charging Him with injustice and cruelty. Many of the people, like Satan, blasphemed God, and had they been able, they would have torn Him from the throne of power. Others were frantic with fear, stretching their hands toward the ark and pleading for admittance. But their entreaties were in vain. Conscience was at last aroused to know that there is a God who ruleth in the heavens. They called upon Him earnestly, but His ear was not open to their cry. In that terrible hour they saw that the transgression of God's law had caused their ruin. Yet while, through fear of punishment, they acknowledged their sin, they felt no true contrition, no abhorrence of evil. They would have returned to their defiance of Heaven, had the judgment been removed. So when God's judgments shall fall upon the earth before its deluge by fire, the impenitent will know just where and what their sin is--the despising of His holy law. Yet they will have no more true repentance than did the old-world sinners. {PP 99.3}

"By the word of God . . . the world that then was, being overflowed with water, perished: but the heavens and the earth, which are now, by the same word are kept in store, reserved unto fire against the day of judgment and perdition of ungodly men." 2 Peter 3:5-7. Another storm is coming. The earth will again be swept by the desolating wrath of God, and sin and sinners will be destroyed. {PP 101.1}

Numbers 21:6 And the LORD sent fiery serpents among the people, and they bit the people; and much people of Israel died. The deaths were due to the withdrawal of the protecting hand of God. The part of the country through which they were traveling was infested with snakes, scorpions, etc. (Deuteronomy 8:15); hence, every day provided miracles of divine protection. But now the Lord withdrew His protection and allowed the snakes to attack the people. Great Controversy: God does not stand toward the sinner as an executioner of the sentence against transgression; but He leaves the rejectors of His mercy to themselves, to reap that which they have sown. Every ray of light rejected, every warning despised or unheeded, every passion indulged, every transgression of the law of God, is a seed sown which yields its unfailing harvest. The Spirit of God, persistently resisted, is at last withdrawn from the sinner, and then there is left no power to control the evil passions of the soul, and no protection from the malice and enmity of Satan. The destruction of Jerusalem is a fearful and solemn warning to all who are trifling with the offers of divine grace and resisting the pleadings of divine mercy. Never was there given a more decisive testimony to God's hatred of sin and to the certain punishment that will fall upon the guilty. {GC 36.1} Malachi 3:6 For I am the LORD, I change not; James 1:17 Every good gift and every perfect gift is from above, and comes down from the Father of lights, with whom is no ficklenss, neither shadow of turning. 1 John 1:5 This then is the message which we have heard of him, and declare to you, that God is light, and in him is no darkness at all.

Will the wicked change after the close of probation? No. IF God is the acting subject in the 7 last plagues, then God is torturing the wick of that time for what purpose? To inflict pain a suffering? No, God is not the acting subject. It is God's withdrawing His hand of protection that gives Satan free reign and as in with Job, it is Satan that is the cause of the 7 last plagues. Satan is the destroyer, God is the restorer.

APL, we cannot force every incident to fit the "withdraw and permit principle of punishment". The Bible and the SOP are too plain, too explicit. To insist evil angels cause the seven last plagues and then fear and tremble at the results elicits visions of mad scientists and exploding beakers and chemical burns. It just doesn't fit. Evil angels are not ignorant, bumbling fools. It is naive to think otherwise.

PS - Do you think Jesus is less culpable when He permits evil angels to inflict suffering and death?

To what purpose does Jesus permit evil angels to inflict suffering and death?

EGW: It is true that all suffering results from the transgression of God's law, but this truth had become perverted. Satan, the author of sin and all its results, had led men to look upon disease and death as proceeding from God

Please explain how the passage you posted above answers the two questions posted above. Thank you.

In the judgment of the universe, God will stand clear of blame for the existence or continuance of evil. It will be demonstrated that the divine decrees are not accessory to sin. There was no defect in God's government, no cause for disaffection. {DA 58.1}