Phase Level

Description
Essentially difficulty level, this stat indicates how threatening enemies are while also affecting score in a number of ways.

In the main game, the initial and capped Phase Levels are defined by the game's chosen difficulty setting: In Demonic Challenge and Matrix Orders, Phase Level is fixed at 11.
 * Novice: Starts at 2, maximum 2.
 * Revised: Starts at 4, maximum 5.
 * Unlimited: Starts at 8, no maximum.
 * Demonic: Fixed at 11.

In Ain Soph Aur the Phase Level setup is the same as Unlimited.

Influences
A death decreases Phase Level by 1, as does use of a bomb. For counter-bomb use, Phase Level only decreases by 1 in total (that is, not once each for the death and bomb use as is the case with Ability Level).

If the Phase Level is lower than the difficulty level's default when an onslaught happens, it is raised to that.

If Eryth overheats, Phase Level is raised by 1.

Performing a Friction Break increases Phase Level by 1.

Every time a named enemy is defeated, Phase Level increases by 1.

If a life extend is earned by passing a multiple of 1,000,000 points while all lives are remaining, Phase Level is reduced by 1.

During a Demonic Shift, Phase Level is set to 11. This is the only way to exceed a difficulty level cap, and as it is not available in Novice mode, this only occurs in Revised. When Demonic Shift ends the Phase Level is returned to what it was before it began.

Effects
Phase Level dictates how many enemies behave; particularly the appearance patterns of regular enemies, and the style, number and/or speed of their attacks. The health of most enemies is affected by Phase Level as well.

It also has many effects on score including its part in area bonuses, onslaught bonuses and defeat bonuses.

The Phase Level throughout a game is averaged (always rounded down) and this plays a part in the calculation of Ability Level.

Phase Level needs to be at least 5 following defeat of Elixirel Kaether in the main game for Elixirel Daath to have a chance to appear.

Exceptions
Not all enemies are affected by Phase Level.

The "true last boss" enemies of the main game (Elixirel Daath) and Ain Soph Aur (and all forms of Matrix Lord Lotus) behave identically at all Phase Levels.

The Matrix Masters' bullet patterns and speeds appear to vary slightly at different Phase Levels. If not for that, it wouldn't matter that Matrix Orders mode was locked to phase level 11.