Board Thread:Legitimate Canon Questions/@comment-122.176.255.207-20140316190353/@comment-4091815-20140316193808

Much of this is explained in Visionary and on the Nemeton page for that matter.

The Nemeton is a big druid power battery. They held their ceremonies and sacrifices there. It was sacred to them.

It also acted as a beacon - meaning supernatural creatures could sense it's power and were drawn to it. Possibly, this is why Noshiko Yukimura was drawn to it while being chased by dogs from the internment camp in The Fox and the Wolf.

Once the tree was cut down - the druids stopped worshiping there and the tree's power diminished over time.

When Derek Hale killed Paige down in the tree's root system, that re-energized the stump a bit.

Then, when Julia Baccari was all slashed up from her encounter with Kali, she sucked out that little bit of power and was able to survive.

When the kids went in the tubs to save their parents they restored the stump to it's full power level. This was followed directly by Julia/Jennifer/Darach causing the storm to end all storms and the earthquake around the stump.

Julia physically released the Nogitsune and, with a fully charged Nemeton to draw on, he was able to do everything we've seen so far.

Also important to point out in all this - the power of the Nemeton does not favor good or evil - both sides can draw on it.