It didn't take a lot of effort to add the basic patterns of a Memory to the weave of the black mantle. That was what he had been doing over and over again to supply the Brilliant Emporium with inventory, after all. By now, weaving them was almost muscle memory.
They did not put a lot of pressure on a weave, either. Even Dormant Memories of the First Tier could bear the weight… the nexus of the mantle had been fashioned out of a Transcendent soul shard, so Sunny did not even have to integrate a second node into the ethereal tapestry.
It was a bit tricky to make the two different schools of weaving flow into each other, but since Sunny's method was the more intricate one and not the other way around, solving that problem proved to be trivial.
Just like that, he gained a new Memory at the cost of a few shadow strings.