The Old Lords with a full mastery of Kevin's lore could have and did unleash power like has never been seen since in the Land.bikebryan wrote: All we know about Trothgard was that it was the site of the final battle between the old Lords and Lord Foul's armies. In the original Chronicles, it was stated that Trothgard smoked and "bled" for centuries after that battle. It wasn't until the Lords found the second ward that they found ways to start the true healing of Trothgard.
That does, however, give me some idea of the SCALE of that powers that must have been unleashed on both sides. We see the power of the Raver/Illearth Stone/Staff of Law in TPTP, yet it produced nothing like the description of Troghgard.
The basic problem is that Earthpower alone is not an answer to Foul. He's basically immune to Earthpower, which is why the power of command doesn't affect him and the Elohim are powerless against him (probably why he's so comfortable in an alliance with Kasty).
I'm sure the Old Lords could destroy huge tracts of land, kill thousands upon thousands of Foul's lackeys in battle, decimate whole geographic features like mountains. But in the end Kevin realized that all the Lore in the Earth would be insufficient to stop Foul.
But it would have been awesome to see one of these Lords in battle with a full mastery of the Seven Wards.