Caveat: Although the legend overlaps with events in the Gospel, it is an extra-Biblical story. That doesn't mean we should automatically dismiss it as fiction, but we should be aware.
|A couple of thieves killing St. B for the Holy Gourd|
Having raised some objections, let's grant that Jacob has a bowl stained with the Precious Blood and Water. In time, he put oil into the bowl, and the oil produced miraculous healings. As Jacob neared death, he entrusted the bowl to two desert hermits. They in turn entrusted the bowl to today's saint, Barypsabas. He continued to use oil from the bowl to perform miracles.
The martyrdom of Barypsabas is variously told. In one account, he was murdered by a couple of thieves who wanted the magic bowl. Of course, it availed them nothing. I can't find the details of this version, but if I were telling it, bad things would befall them and all their works would be undone. I am not sure if the bowl would be lost with them, or if they would repent, entrust the relic to a monk, and live the quiet lives of holy hermits.
In another account, he took the bowl to Rome, but then went on to Dalmatia, where he was martyred. It's a fun story, but I am not sure it highlights any particular virtue or course of action. Perhaps if more details of his martyrdom had survived.