There are 25 total Tuning Stones you can acquire in
Next, there is the Genesis Uber Tuning Stone, which has a completely different effect than the Evernight. The effect is as follows: “Increase the effectiveness of the Supported Skill by 150%.”
The methods to acquire the Genesis stone is the exact same as the Evernight stone. Once again, your best chance to earn the stone is defeat the Echo of Malphas. This means defeating the boss has the potential to drop either of the Uber Tuning Stones, so your odds of landing one of them is decent, relatively speaking.
You will probably have to practice extreme patience when trying to get either of the Uber Tuning Stones, so don’t expect to get it quickly. Of course, if the RNG is on your side, you could have your Seneschal decked out with an Uber Tuning Stone or two faster than you expect.