Dusk Diver 2

MISSABLE

See This Is...?!  for more information on Orbs and crafting them.

You likely won't be able to get this trophy much later in the game, when you're getting equipment pieces that come with multiple Orb slots. There are only 4 Equipment Slots per character; 

1. Weapon (Max Orb Slots: 2),
2. Head (Max Orb Slots: 3),
3. Body (Max Orb Slots: 3), and
4. Accessory (Max Orb Slots: 3).
    

Because of that, to reach 9 Slots of Orbs, you need at least an average of 2 Slots per piece, but will likely need at least 2 items with 3 Orb Slots. Unfortunately, the first time you'll receive an item with 3 slots isn't until Chapter 11, so that's probably where you'll earn this trophy.

Note: There's a reason why the trophy description says "9 slots' worth of Orbs..." This is because not all Orbs fit in 1 slot. You'll notice fairly early on that some Orbs require 2 or even more slots to be used (see below). This means that you won't necessarily need 9 Orbs, just 9 slots' worth. For example, you could get this trophy with only 3 Orbs, if each Orb is worth/requires 3 slots.

To know how many slots an Orb requires, look at the number of gems listed by the orb's name. In the example image below, SP Orb I and Wafer Orb I require 2 slots each, versus just 1 slot for all the others on the list.