Forged Destiny [Book 9: Ch. 13]

The ground split behind the line of Heroes and Soldiers, but the thing that came through was not blackened Grimm flesh but bright silver metal.

Living metal.

Ironwood.

It sang to me – singing joyously as it grew and grew, blossoming over the heads of the Heroes and crashing into the Grimm beyond. The root, for it was shaped like the root of some giant tree, twisted and bulged, breaking the ground further as the thick mass came forth, piercing through Grimm and slamming down onto, and into, the ground, digging back through solid rock on its journey toward the gate.

[...]

I could feel the energy within it. No doubt Ironwood's, the Archmage, feeding his magic through its porous structure. Even then, it felt weak and diluted, understandable given the vast distance between this offshoot and the CCT.

[...]

No one got in my way as I reached the root, easily twice the width of me, and laid my hands upon it.

Immediately, I could feel the way the magic flowed through it. I didn't know why. There was no Skill I had that should have let me do it. It felt more like the Ironwood was showing me. Or just brimming with so much power that it was tangible. I closed my eyes and concentrated. It was like Penny in a sense, warm and alive. And it wanted to grow. I knew that now, knew it from the sheer joy it exuded as it tore through the Grimm.

[...]

My hands burned. Like before, the heat was swept away so easily by the Ironwood, siphoned and spread throughout the full length of it. Instantly, I knew this root was connected to the CCT. It wasn't made closer. It had come from the CCT, directed by the Archmage underground and probably guided by the Augurs he and Winter would be watching the battle through.

—Forged Destiny [Book 9: Ch. 13]