How to get the rifle with exotic traces effigy ruinous in Destiny 2 – Guide to the quest for growth
Step 1: Missive
Go interact with the prismatic recaster in the tower to get the growth quest.
Step 2: Gift
You have to finish the weekly average end quest. Make the public contact event, then recover the traces of Umbrals, then finish by performing the interference mission on IO. Interact with darkness near Eris when it is finished, and this will take you to the next step.
Step 3: Pendulum
You must collect calcified fragments of light on IO, Titan, Mars and Mercury. There are five on each planet, and your ghost will show you where to go if you hold it.
You must also find the Savathun puppets on IO and Titan. To find them, search in areas that do not have a public contact event. You should be able to find plagues, and when you destroy them, the bosses will appear. Kill them, then a champion will appear. Here is the puppet.
Step 4: Food
You will have to defeat enemies with vacuum damage, chain precision eliminations and finish gambit or reckoning matches. You can quite easily catch the victims by playing one or the other of the modes.
Step 5: Form
Return to Prismatic Recaster to get your reward.