Simple Examples:
* The onus is on the prosecution to prove the defendant's guilt beyond a reasonable doubt.
* The onus of responsibility for the project's success falls on the team leader.
* After the accident, the onus of proving negligence fell on the driver.
More Complex Examples:
* The onus of adapting to the changing climate rests on the shoulders of both individuals and governments.
* The company faces a heavy onus to maintain its reputation after the recent scandal.
* Despite his wealth, he felt a great onus to help those less fortunate.
Note: "Onus" is often used with "on" or "upon" to indicate who or what bears the burden.
Let me know if you'd like more examples or have any other questions!