David Lieberman aka Micro could've been a goofy, disposable comic relief character and not much more, but thanks to sharp writing and Ebon Moss-Bachrach's nuanced performance, he ended up one of the show's few truly likeable characters.
When the series begins, Micro is in hiding, having previously faked his own death in order to protect his family, and ends up working with Frank Castle to expose Agent Orange's shady government operations.
However, in the show's penultimate episode, Micro is forced to fake his death for a second time during a prisoner exchange for his wife and son, being apparently killed in a shootout between the cops and Anvil operatives.
However, moments later, when Micro's bodybag is unzipped, it's revealed that he's pulled another sneaky sleight-of-hand with the help of Dinah Madani. Considering how fantastic a character he is, it was a huge relief that he lived to fight another day (and another season).