Satan “wins” in gathering souls to himself - evil - and from God. He’s in a contest to control humanity and make people suffer. He hates God and looks at man, whom God created and loves, as a dispicable creation. He hates human life. Satan mocks God by showing Him how people are evil; falling to Satan’s call to do the opposite of what God wants and rejecting God and what He created man to be.
Satan will have his time on earth to recruit and harm people, then he’ll be cut off. He hates humanity - God’s creation and he hates God. In the end days he’ll work fast and furious to reap souls (people who fall to evil and who reject God and His nature). Satan enjoys the imposition of torment, suffering, fear and death on humanity because he’s at war with God who loves mankind. Fallen humanity is Satan’s prize.
So if we think about it... Satan starts with everyone already his. Right... we’re born into sin since the fall. He doesn’t have to work to get anybody on is side. They are already there. He doesn’t have to recruit anyone. He doesn’t have to gather souls to himself. They start out as his since the fall. God’s side has to work to reclaim them.
...In the end days he’ll work fast and furious to reap souls...
Pastor Mike Hoggard has a couple of presentations that back up your fast and furious assertion. And it’s in a field most people do not yet think of as capable of deception on such a grand scale.
The most recent: http://watchmanvideobroadcast.com/video/wvb120930_rewriting-the-book.html
Link to the video he suggests you see first, Jesus Christ, DNA and the Bible:
https://www.youtube.com/watch?v=iDH6ruRheyk