Keanu tries to shoot Satan, but his bullets have no effect, because Satan eats AK-47s for breakfast. Since simply not screwing his sister is apparently not an option, Keanu, in a shocking twist ending, turns the gun on himself and blows his brains out, fucking up Satan's whole plan.
This was also his exact reaction to the Sad Keanu meme.
The twist ending is not so shocking when it happens again in the film Constantine, in which Keanu portrays a modern-day exorcist who must stop Satan's son, the demon Mammon, from taking over the Earth behind his daddy's back. Knowing that his own soul is damned to hell because of all those times he cheated in Monopoly, Keanu cleverly slits his wrists specifically so he can have a chat with Lucifer and rat out Mammon.
How many black suits has Keanu ruined in his career?
After he has dealt with Junior, Satan tries to take Keanu's soul to hell, only to find out that he can't because Keanu's been redeemed by his self-sacrifice. So, instead, he begins ascending to heaven.