“Overcharge” Boss immunity
Mentioned above, but as it stands, Indivilia is the only boss that can do this. She will shrug off all debuffs and make herself completely immune to debuffs while in this state. She is not inherently tankier than other bosses, but being unable to shred defense or have her take more damage makes reaching stages significantly more difficult.
Summoned Raptures
During both phases of the fight, Indivilia will summon flying raptures from the back of the screen that are considered “invisible”. The game says they cannot be targeted, but testing seems to show that they can, these flying raptures can be destroyed. They do heavy damage to whoever it targets, so destroying them as soon as possible is highly recommended.
Targeted Lasers (Pincers, Tail, and Core)
Every so often during the fight, Indivilia will charge up an attack from both of her pincers and her tail, dealing heavy damage to a NIKKE. These parts can be broken, but will respawn after a certain amount of time has passed.
This targeted laser cannot under any circumstance be taunted or attracted to by another NIKKE. The only way to avoid this is by tanking and recovering or taking cover, or the easiest is by destroying the parts to avoid it altogether. The tail can be really tough to hit because it moves around the screen a lot, but it has low hp and does not take a ton to break.
For those who are familiar with the solo raid version of the boss, not breaking the tail eventually lead to a charge up attack that killed the entire party. The Anomaly interception differs in that if you do not break the tail, the boss will eventually deal an attack that pierces cover and instantly kill a NIKKE.
There are individual other attacks from the pincers and tail as well that are also targeted but do not deal bonus damage to NIKKE. They are normal attacks that deal moderate damage and can be taunted, or avoided by destroying the parts.
Another charged laser attack can be avoided from the core of the boss, it is fairly obvious when this attack occurs as the boss will essentially be doing nothing else while it performs this attack. It can be covered, but not taunted.
Super Quiver Blade (Interrupt)
This is a 4 cancel circle interruption, the boss will do this attack regardless of whether the tail is broken. This sequence can only be done with FIRE element code NIKKE and must be interrupted, or the boss will swipe across the screen with its tail, killing all NIKKE and ending the run. The cancel circles themselves are extremely easy to break, so even a single fire code NIKKE should be able to deal with this if you are lacking units.
Second Phase mechanics
A few mechanics continue from the first phase, but the second phase is mainly a damage rush to the end. The boss is extremely aggressive in this phase and will continuously attack, high recovery and understanding damage thresholds for attacks is extremely in this phase as well as careful control of summoned breakable missiles and laser attack targets.
Stage 6 example run by Riza
Stage 5 example run by Tharsis