Quick answer
What a person is made of does the protecting, or the toppling. The verse assigns the active role to the character rather than to an outside force.
Read both lines
This restates 11:3 and 11:5 with the same structure and the same theology of consequence. Righteousness guards, using the guarding verb from 4:23, so integrity functions like a sentry; wickedness overthrows, and the one it overthrows is the one who has it. Nobody administers either outcome. This is the book's steady claim that conduct grows its own results under God's government, which is a different thing from a scorekeeper handing out verdicts, and it is why these verses so rarely mention God at all.
Related: Proverbs 11:3 · Proverbs 11:5 · Proverbs 5:22
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.