Your managers demanded a stupid feature, and you took long time implementing the stupid feature due to its complexity.
The only thing missing is you need to warn your managers before you start coding such as "This is going to take long time due to the complexity, many many weeks. Also I don't think it's right for the product either."
As long as expectations are clear beforehand, and you met those expectations, then no one is getting fired, and therefore you should relax and enjoy coding Easter Eggs into each shitty feature.
Your managers demanded a stupid feature, and you took long time implementing the stupid feature due to its complexity.
The only thing missing is you need to warn your managers before you start coding such as "This is going to take long time due to the complexity, many many weeks. Also I don't think it's right for the product either."
As long as expectations are clear beforehand, and you met those expectations, then no one is getting fired, and therefore you should relax and enjoy coding Easter Eggs into each shitty feature.