Red Orbs are dropped by every enemy and are the form of currency in Devil May Cry. Thankfully, this trophy is cumulative over your multiple play throughs, so without a doubt you should have all three Red Orb-related trophies by the end of Dante Must Die mode. You shouldn’t have any reason to worry about this.
A good way to get orbs fast and easy for me was Mission 19, the 3 monsters that are laughing like hyena they give good orbs and you can shotgun them all with piercing damage if your lucky for a bit, then just fly around air raid, leave area rinse and repeat, at least 400 orbs no more than 45sec-1 min