The tumor’s programming
As the Aspect of coming unpleasantness, Doom has a heavy connection to prophecy, to rules, and to consumptive flames. Few things in Homestuck symbolize these things as well as The Tumor, the great bomb which waits at the end of the troll and human universes and uses the energy from their twin destructions to create the mother of all explosions, and the red and blue of which marks Sollux’ personal iconography.
Oh, and it marks him in another way, same as it marks the entirety of Act 5.
Remember this code? http://mspaintadventures.com/?s=6&p=003926
This code was created by Sollux. This code, when run, causes an explosion, and lays a curse. This code describes with precision the behavior of the Tumor.
The Tumor causes an explosion when run, and in creating the Green Sun can certainly be said to lay a curse.
The text of the code itself? It separates the program into two halves, one red and one blue, associates the termination of each half with a universe (the red Earthly universe is marked U1, the blue Alternian universe is marked !U2, or “not U2”, an early reference to the fact that the Alternian universe is the result of a scratch). Upon the simultaneous termination of both these universes, the code vaguely resolves itself, and the Tumor explodes.
In other words, and this is where I delve into straight up technobabble, by the act of resembling the structure of the Tumor, Sollux’ little piece of code becomes notionally entangled with the Tumor, such that the running of the code is circumstantially simultaneous with the exploding of the tumor. Since the code is thus essentially a lesser echo of the Tumor, it gains its properties, and causes explosions and misery in what can only be described as an act of sympathetic magic.
Oh, and I mentioned something about the Tumor marking the entirety of Act 5? Take a look at the Homestuck map http://mspaintadventures.com/?viewmap=6 and scroll down to Act 5. “import universe U1”, “import Universe U2”, and right by the link to Cascade, the flash in which the tumor itself detonates, “[THIS, THIS].DIE();”