There are very few challenging trophies in Void Terrarium. Most of them hinge on doing something a lot, normal progression or just being, of all things, lazy. Void BeWithYou() is actually quite a bit different. Despite being a rather simple trophy, at least in concept, what you need to do and how you do it is actually rather long, tedious and annoying.
Find a Moonstone
Before you can worry about getting the trophy, you need to obtain a Moonstone. This is an extremely rare drop from the suicide bomb robots, meaning you need to either get lucky through normal progression or start to farm the endless dungeon.
What makes the endless dungeon the ideal place to farm this is due to the fact you could potentially hit the level cap of 99. Your goal, beyond staying alive, is to simply get as many Drop Rate Up items as possible. With two it should be relatively obtainable and with three you can probably get every rare drop in the game if you give it enough time. The best way to ensure you get that benefit is by equipping both Extra Skill Draws.
Upon obtaining it and however many items you find, return to the terrarium to obtain the blueprint.
Making the Moon
How long this takes ultimately depends on how many new rare drops you obtained. Basically, Void Terrarium will only tell you about a single new blueprint after each run, so you’ll need to load up a level and leave instantly. You want to keep doing this until you run out of new blueprints or at least obtain the Moon blueprint.
For this you need the aforementioned Moonstone, along with four green and blue resources. By this point it shouldn’t be too difficult to obtain but in the event it is, just run some low level areas and exit as soon as your inventory is full.
Unlocking the Trophy
Making the Moon is not enough to unlock the trophy. Unfortunately, you need to also place it somewhere in the terrarium and wait for Toriko to notice it and sit down. She should do this relatively quickly, though there is no guarantee. Once she does this, simply walk over, press X to sit with her and you’ll both look at the Moon and the trophy will unlock.