Crucia and Regulos would use the Infinity Gate to win the war, but it can only be powered by the Nexus Key, which amplifies magic. The Shapers store its power in crystals from which they draw strength while entranced.
Destroying these crystals could kill many Shapers, but you will need to use a Soothing Stone to keep them asleep while the bomb charges.
I'm glad you were able to keep those Shapers subdued until the bomb went off. Those were some of their stronger ghouls, which means they'll be less likely to fend off our attack.
If everything goes well, we'll end the Shaper threat forever.