The day either of these giants reaches our orbital borders will be a day not soon forgotten. For your pleasure, A Borg Cube vs. a Reaper

Stats:

Name: Something Ominous
Franchise: Mass Effect
Type: Reaper
Faction: Reapers
Dimensions:
Length: 2 km
Structural Layout: Reaper Cuttlefish. Indeterminate weak points
Offensive:
• Hull (was shown ramming a Turian Cruiser to hell in Mass Effect)
• “magnetohydrodynamic” weapon on each arm/tentacle/thing, firing a beam of molten iron-uranium-tungsten alloy at relativistic velocity
• Spinal-mounted weapon, capable of tearing through very large ships with little effort (likely significantly more powerful than the arm-mounted weapons)
Defensive:
• Hull (hit a Turian ship, Turian ship hits you just as hard)
• Shields capable of withstanding several fleets worth of firepower
Sublight: Unknown
FTL:
• FTL Drive: Reduces the mass of a starship, allowing it to travel faster than light
• Mass Relay Network: creates a mass-free “corridor” between relays and propelling starships along these corridors fast enough to make the series ‘Star Trek: Voyager’ last less than 3 episodes. Requires a Mass Relay
Power Plant:
• Massive Element Zero Core
• Unknown
Extra:
• Capable of indoctrinating organics
• Likely use nanotechnology
• Techno-organic lifeforms
• Capable of making, supporting, transporting, and deploying Husks (Reaper ground force/drones)

Name: Cube ###
Franchise: Star Trek
Type: Cube
Faction: Borg
Dimensions:
Length: 3 km
Width: 3 km
Height/depth: 3 km
Structural Layout: Cube
Offensive:
• Tractor beam capable of draining shields and inflicting hull damage
• LASER cutting beam (exactly what it says on the tin)
• Missile weapon capable of disabling a Galaxy-class ships shields and warp drive
• Beam weapons (little data)
Defensive:
• Dispersal fields capable of disrupting sensors and blocking transporters
• The ability to adapt to almost anything
Sublight: Impulse Drive?
FTL:
• Warp drive
• Transwarp drive
• Transwarp hub (requires aperture)
Power Plant: Redundant power sources, capable of supplying seamless power to the whole ship even if one or more are damaged or destroyed
Extra:
• Capable of holding up to 3,000+ Borg Drones
• Capable of remaining operable if 78% damaged or destroyed
• Capable of regenerating (Q Who, Best of Both Worlds P. 2)
• Highly adaptive
• Resistance is generally regarded as futile