We should’ve been ripped to shreds by Rhulk but we beat him cuz plot

Technically, it's not really guns that destroy gods. It's guardians. This is weird, but bear with me. It's similar to how ghosts can only be killed by paracausal means (Edit: it is very hard to kill a ghost without paracausal means; think the Marksman Scorned Baron, the light-siphoning swords of the hive, and the creatures the Drifter encounters on his travels); meaning that things like darkness-infused light-siphoning Hive swords and guardians and Darkness-revived-Scorn crossbows are (some of) the only things that can destroy Ghosts. Similarly, normal causal things (like human, exo, or awoken hands) can't destroy Ghosts on their own (or it is very difficult to). Huge explosions and stuff can still kill the paracausal beings known as ghosts, but it's extremely difficult to do. However...how is it in Witch Queen that we're able to crush ghosts with human (exo, or awoken) hands? It's because we are beings of paracausality. A normal mortal couldn't crush a ghost with his or her bare hands. That takes a guardian, aka a being of paracausality (essentially, we are above the rules in this respect). So it's not that the witness is going to get beat with guns. If the wielders thereof were mortal beings, unblessed by either light or darkness, they would have a much greater problem defeating the Witness (aka, a chance of almost 0%). But since we're guardians, we have a chance. We are above the rules of normal causality. We can beat the Witness with guns (heck, we'd even have a chance with [i]sticks[/i]) where others cannot.

When some of our guns are actual gods or time altering machines.. I CAN see this happening.

i bet we’ll fight the witness beneath a shattered or shattering traveler, and he’ll die by the traveler blasting him with a pillar of light. there’ll be some mechanic that the guardians do to channel the traveler’s light beam, maybe a prism of some kind that makes it burn extra hot

They once said Crota could not be killed. They once said the same of Oryx. They once said the same of a Hive Worm god. They once said the Vex were unstoppable, and the Vault was unconquerable. They once said you couldn't wield darkness without losing yourself to corruption. They also once said you can't shoot yourself out of a cannon to board a Hive ship. [spoiler]Nor could you just shoot a hole into Mars.[/spoiler] Every time, proven wrong. We will find a way. It's what we do. Whether it is with our guns, our fists, our powers, our skill, or our cunning we will find a way to break the Witness and her little fleet. Anything that stands in the way of humanity's survival [b][i]must[/i][/b] be broken, [b][i]will[/i][/b] be broken. Just a matter of determining the means.

Well the guns in this game are magical as F. You have a rocket that tracks and splits into Wolfpack rounds. We have sleeper which is an overcharged red laser beam, its not like we are gonna use regular weapons.

What if I shoot a nuclear worm at them? Is that a little less silly?

Gjallarhorn kills everything, ask Crota

Well, guns have worked on every other big bad so far.

I genuinely doubt we’re going to fight him in any even vaguely traditional way, if at all.

To be fair we didn’t just get rid of oryx by shooting him with a gun. It sure was a part of it though.

Probably will be a Oryx type fight

Savathûn's ship will make the Traveler into that "Pyramid bomb" you see in the public event. What happens when you hit a Pyramid/prism with a focused beam of white light?

50 cal, rockets, didn't do a thing