This is last possible gameplay area in Resident Evil: Revelations 2, here the player can only control Claire or Barry, the character changes automatically based on where Barry and Alex are standing - if Barry is outside, Claire will be playable, if Alex is inside any of the caves, the game will switch to Barry's perspective.
There is one Tower Emblem in this area which can only be accessed by Claire, whenever Claire is in control, look at the top of the cliff, the emblem is somewhere up there. (because the helicopter changes its location often, it's inaccurate to say which side the emblem will be)
Claire is also only equipped with the SVD Rifle, however, it has infinite ammo. Once enough damage has been dealt, she will grab a Rocket Launcher that's sitting in the helicopter. Alex can only be defeated by shooting this RPG at her, any other type of damage will not kill her, even if Barry has the Rocket Launcher ∞.
The best strategy to defeat this boss is to play as Claire as much as possible because she has infinite ammo and can't be damaged. Whenever Barry is in control, simply run away towards the ouside area and shoot Alex away as Claire. Be careful though, as each time Barry is in control, certain small masses of Uroboros tentacles will be on his way, which when stepped on will trap Barry in place. Shoot them before running, though unlike the same mass dropped by the Uroboros Aheri, these won't drop any type of ammo or item.
In the Invisible Mode, although Alex will be completely invisble, it's still possible to know where she is based on the light that comes from the helicopter. Wherever it's pointing, that's where Alex is.
Additionally, both Moira and Claire have a different costume when playing this sequence, Claire will be wearing her Sniper costume and Moira will be wearing her Survivor costume by default. Although Natalia has a few dialogue lines, it's not possible to turn around to see her inside the helicopter through natural gameplay.
- Tada, Takuji, ed (2015). BIOHAZARD REVELATIONS 2 ULTIMANIA. Square Enix.
- Tada (ed.), Ultimania, pp.188-189.