Engineering


The Echidna is divided into two actors:
Echidna describes the magic wielding woman on one end
Snake refers to her independently acting tail that ends in a snake head.



The fight is divided into four phases with recurring but modified attack patterns & parameters that need to be adjustable by the Designers and QA which are as follows:
Attacks
Swipe I
Actor
Echidna
Adjustable:
Speed of attack
Speed of animation
Starting point cones (l,r)
Echidna idle time
Damage of attack
The Echidna sends long waves across the level that can be dashed through and blocked by the shield. Three horizontal thin cone shaped waves from the sides of the level and one vertically extending thin half circle waves attack from the Echidna.
The pattern can be left, right, left, Echidna, or right, left, right, Echidna
It cannot be interrupted
After the last swipe, the Echidna is idle for a little while



This attack ignores all environmental obstacles
This attack blocks all other attacks from happening, the snake is idle
Swipe II
Same pattern, adjusted speed & damage
This attack ignores all environmental obstacles
This attack blocks all other attacks from happening, the Snake is idle


Magic Toss I
Actor
Echidna
Adjustable:
Speed of bombs thrown back to back
Speed of fly arc
Damage of bombs
Amount of bombs thrown per attack
The Echidna locks onto Zagreus and throws multiple magic bombs to his position.
The bombs aren't homing. They work similar to the Inferno-Bombers single throw attacks but they have clear cross-hair type telegraphing on the floor while they're thrown, like the Fireballs in Asphodel.

This attack ignores all environmental obstacles
This attack does not block the other actor from attacking

Magic Toss II
Same pattern, adjusted speed & damage & amount
This attack ignores all environmental obstacles
This attack does not block the other actor from attacking


Poison Spit
Actor
Snake
Adjustable:
Size of Clouds
Speed of fly arc
Damage of Clouds over time (like magma)
Amount of clouds thrown per attack
Duration of Clouds
The snake spits several clouds of a poison gas to random points of the level that deals damage over time in an area, similar to the Fireballs in Asphodel.
The landing point of the clouds is clearly telegraphed, like the Fireballs in Asphodel.

This attack ignores all environmental obstacles
The duration of this attack does not block any other attacks from happening
This attack does not block the other actor from attacking


Snake Strike I
Actor
Snake
Adjustable:
Speed of Strike
Size of AoE
Damage of AoE
Duration of Hold /Stun
Speed of Retreat
Reach of the strike
After generous telegraphing with sound, animations, and effects, the Snake strikes to Zagreus position or direction, dealing damage in a small AoE.
It retreats immediately.
Its body blocks the way but is dash-able, deals no damage, and takes damage.
Its head does not deal damage on retreat, only on the AoE strike to the floor.

This attack destroys obstacles in the way
This attack does not block the other actor from attacking
Snake Strike II
Similar to Snake Strike I with following differences:

The Snake strikes at Zagreus' position, dealing damage in a big AoE to the floor.


There, it remains stunned for a bit.
Like in Snake Strike I, its body and here its head block the way but are dash-able, deals no damage, and takes damage.
After a bit, it retreats and can perform other attacks again.


This attack destroy obstacles in the way
This attack does not block the other actor from attacking


Snake Leaps I
Actor
Snake
Adjustable:
Speed of Leaps
Impact AoE Size
Damage of Impact
Duration of Body Pulse & Downtime
Damage of Body Pulse
Duration of Phase Telegraphing
Health percentage of when Body Pulse starts
The Snake takes full control of the entirety of the Echidna.
It roars, then leaps into the Erebus pools in the level, dragging its body behind and dealing AoE damage with every new leap into a pool.


It follows Zagreus around through the pools of Erebus in the level.
The length of its body creates dash-able walls that also take damage.


At n% of health, the length of its body deals periodic pulses of damage during which Zagreus cannot touch it without taking damage.


Attack ends with invulnerable Snake & with an animation, similar to Minotaur mini boss fight.


Snake is invulnerable during start & end animation
The Echidna is not present as an actor during this attack as it gets dragged behind the snake body

This attack ignores all environmental obstacles
There aren't any other attacks than this in Phase 2

Snake Leaps II
Same as Snake Leaps I with following differences:

Starts when the boss has no health left, takes one hit to take it out
The Snake doesn't follow Zagreus around, the pattern in which it leaps into the pools is completely random now
Adjusted speed & damage
No Body Pulses

Snake is invulnerable during start & end animation

The Echidna is not present as an actor during this attack as it gets dragged behind the snake body

This attack ignores all environmental obstacles
There aren't any other attacks than this in Phase 4



Summons
Actor
Echidna
Adjustable:
Amount of summoned actors
Amount of projectiles per attack per summoned actor
Amount of attacks
Damage of projectiles & lava pools
Speed of projectiles
Duration of lava pools

The Echidna summons Wave Hydra Support Heads, Magma Spittle Hydra Support Heads, or Gorgons into the fight with their usual attacks but altered behavior:
The summons keep at the sides of the level and cannot be damaged.
The summons attack n amount of times and disappear again.



The waves ignore all environmental obstacles



This fireballs ignore all environmental obstacles



The gorgon projectiles get blocked by obstacles

The initiation of this attack blocks all other attacks from happening

Phases & Attack Combinations
Adjustable:
Health
Health % for Phase change
Loot drop

Phase 1
Swipe I
Magic Toss I
Poison Spit
Snake Strike I
Start:
- Music
- Boss Introduction Animation, Effects, Sound
- Dialogue (UI & Voice Acting)
- Phase 1 Attacks
End:
- Actors become invincible
- Actors go back to their point of origin
Phase 2
Snake Leaps I
Start:
- Snake Leaps Initiation Sequence & Telegraphing
- Level Design changes, if present
- Snake stops being invincible, Echidna is inactive as an actor
- Phase 2 Attack
End:
- Actors become invincible
- Snake Leaps end animation
- Actors go back to their point of origin
- Level Design changes, if present
Phase 3
Summons
Swipe II
Magic Toss II
Snake Strike II
Start:
- Echidna telegraphing sound & animation
- Actors stop being invincible
- Phase 3 Attacks
End:
- Actors become invincible
- Actors go back to their point of origin
Phase 4
Snake Leaps II
Start:
- Snake telegraphing, animation & sound
- Snake stops being invincible, Echidna is inactive as an actor
- Level Design changes, if present
- Phase 4 Attack
End:
- Defeat animation & UI
- Zagreus Dialogue
- Loot drop