Death Bombs are dimensional openers capable of sending the victim of the bomb to the end of the dimension. They are a device that was frequently used by the Vexos.
The method of creating Death Bombs is unknown, but it sucks it's victims into a portal. Contrary to the name, Death Bombs do not seem to directly kill whomever they suck in but they instead transporting them to another dimension. It is unknown where the victims are sent to or even if they are still alive after a time.
It can be assumed that soon after being sucked in, they die; Hydron says "Volt, Lync, I'll be there... Soon" as the Alternative was about to explode, an event he was very unlikely to survive.
After the Death Bomb's portal closes, it leaves behind a small crater.
Mylene Farrow attempted to use one within Bakugan Interspace after failing to defeat Spectra Phantom and Mira Fermin, and Spectra looked shocked which means he knows what they are, but the activation started to distort the area instead and caused her and Shadow Prove to get sent to another dimension. Mylene has mentioned that she used them before; it likely had an unexpected effect since Bakugan Interspace is a digital environment and not the real world.