Lol says who? The game is almost a year old. Who is to say we haven't found the other 30 subclasses? Or a new type of light? Yeah no you can't just take a fight and shape it how you want so the other loses and call it a day lol. In a straight fight, full power goku vs full power destiny, nothing short of multiple cabal warships hitting him at once or aetheon sending him back in time, is going to stop him. And even then, he's multitudes faster than the speed of light, and create afterimagez, and could destroy all the warships with a flick of his wrist lol and aetheon just requires him leaving the vault of glass and nuking it or just nuking all of Venus to begin with.

Do I really need to repeat myself? He's going into the games universe, your class determines your subclasses in Destiny; and you cannot use more than one subclass at a time. This is current Destiny rules so he would have to conform to these rules. Also VoGs entrance exists on Venus but its actually in its own time stream. So it's indestructible.

Lol once again I'll repeat myself. Says who? Eris doesn't have a class. Speaker doesn't have a class. Cabal don't have a class. Vex don't have a class. Goku would be a saiyan...a completely different entity, who can draw from the light. Idk where you're getting that he is going to be forced to pick if he wants to be gunslinger or a bladedancer or such lol. Those are purely game mechanics that force you to pick one. And yeah point me to the grimoire which says the door or walls are indestructible

Eris is a Hunter, The Speaker is a warlock. And of course the Vex, Cabal, and fallen wouldn't have a class that's just stupidity on your part. And as he would be forced to use game mechanics as that is the Destiny Universe he would have to have a class.