Eco Risonante

Zone: Zereth Mortis
Source: Protoform Synthesis
Materials:

• 250 Genesis Motes

• 1 x Glimmer of Survival

• 1 x Unformed Lattice

The schematic for the Resonant Echo can be looted from the Crystallized Echo of the First Song.

/way #1970 58.7 89.9 Crystallized Echo of the First Song
/way #1970 77.4 45.4 Crystallized Echo of the First Song
/way #1970 77.4 45.5 Crystallized Echo of the First Song
/way #1970 77.5 60.4 Crystallized Echo of the First Song
/way #1970 77.6 58.9 Crystallized Echo of the First Song
/way #1970 77.6 60.5 Crystallized Echo of the First Song
/way #1970 78.2 54.4 Crystallized Echo of the First Song
/way #1970 78.2 54.5 Crystallized Echo of the First Song
/way #1970 78.4 52.9 Crystallized Echo of the First Song

From Blizzard's Support Article:

To unlock Zereth Mortis, you must have completed Chapter 2 of the 9.1 campaign, Maw Walkers, up until the quest Charge of the Covenants. After that quest is completed, you will receive the pop-up to start the Zereth Mortis campaign.

Protoform Synthesis

Unlocking the Protoform Synthesis Forges requires you to research the Dealic section through the Cypher of the First Ones, Cypher Research Console, and then complete a short quest line.

You will gain access to the Cypher Research Console after you finish Chapter 3 of the Secrets of the First Ones campaign.

To gain access to the Battle Pet Protoform Synthesis Forge, you will need to research Dealic Understanding.

After researching Dealic Understanding, your Pocopoc will provide you with a quest called Protoform Synthesis. Finish this and you will have access to the forge which allows for the crafting of Battle Pets.

The entrance to the Battle Pet Forge is located at /way #1970 61.8 58.8 (Underground)