I've been killing a LOT of flood combat forms and yet, for some reason or another, it's not concluding it at all whatsoever. Is there a specific objective that one needs to complete during this side objective? Like finding an Index-like object? I'm asking since the flood combat forms continuously are shown respawning out of thin air in the small vents, so yeah...

EDIT: Finally figured out the condition needed to pass this obscure-as-f**k side mission: Simply go through it similar to how one treks through in Halo CE, only this time you have a good amount of respawning Banished allies that help back you up. There's flood doors that you need to melee/damage to get through, I often concentrate on the lower-middle piece of each flood door and then crouch through it and then the rest of the pieces script-self-destruct themselves. I find that using the LMG and energy sword is an excellent combo for getting through this obscure side mission.