Fighting New Chaos - Considerations

Canon of Suzumiya Haruhi was taken over.
Canon of Stargate: SG-1 was taken over.
Canon of Star Trek was taken over.
Canon of Star Wars (pre-Yuuzhan Vong Invasion) successfully fought off incursion but unprepared for extra-galactic invasion.

Be prepared for plague bomb attacks.
Danger of Warp-infused nanites.

Enemy has Space Marine infantry.

Exitus Rifle has an effective range of 10 kilometers and has a special Phased Penetrator Round based off of the Lance of Longinus.

Angel Cutter blades based off of the Lance of Longinus are used by Temple Assassins and Hellhound warp demons.

Warp-powered grenade dispensers and other support equipment utilizing teleportation logistics.

Evidence of heavy assault units with mobile anti-magic fields. Culexus will be able to negate most magic, and likely energy weapons. Recommend concentrated kinetic weapons or Aglaophotis.

Hellhound - Assassination and front-line unit. Extremely fast and strong, armed with adamantium phased blades in its arms, a helmet-mounted crystal flechette gun (crystals are coated in a neurotoxin and a possible avenue for Chaos corruption; use Esuna or nanite medical treatments at first opportunity), and photon flash grenades. They are capable of climbing and running along walls and ceilings; expect Xenomorph-like attacks. Experience from Aliens will be somewhat useful. Their ability to use photon grenades will minimize the usefulness of turrets if they are not equipped with flash compensators.
Do not depend on magical wards for protection; the forearm blades will neutralize them like the Lance of Longinus.
Bionics are designed to allow for stealth and noise-cancellation, as well as enhanced senses.
They are also warded; magical attacks may have lessened effects.
POTENTIAL WEAKNESS: Forearm blades are highly conductive to electricity.

Hellhounds are capable of extremely fast Warp-gate opening rituals using sacrifices; from initiation of sacrifice to opening of a portal large enough to permit a daemon entry is under 6 seconds.

Teleportation shenanigans are to be expected.
*** Note: Stealth fields are employed by the enemy; remote scans are not to be trusted. Require visual confirmation. ***

Telepathic communications may be disrupted by Warp rituals.
Possible Weakness: Destroy Chaos Warp Gate - disruption of the Warp's point of entry into a Canon may greatly weaken the enemy, possibly banishing all demon forces.
Similar effects were observed in Canons that do not natively have the Warp.