Board Thread:Questions and Answers/@comment-31725345-20170716102432/@comment-78.194.252.210-20170716190957

A servant is a part of the Heroic Spitit based on Counter Guardian. heroic Spirits are globaally superior if we think about CG like Shirou, but they are also members of the Counter Force like the Beast of gaia.

Servants/CG < Grand Servants < Heroic Spirits

A servant gone mad could be stopped by a CG.

A heroic spirit going mad... could not really, it's all the problem of Fate/Grand Order. A servant going mad could be stopped.

After, there are "special Counter Guardians", like Primate Murder, that could change the wave.