This device is sent from the Future by Morden's own Rebel Army (much to present Morden's surprise), and it's basically a giant, hovering warp portal. Its powers are not limited to summoning Future Rebel infantry and units, but is also able to shoot fast volleys of plasma to the enemy. Before its destruction, it summons the Kraken to rescue Morden.
Despite Morden standing there and commanding during the fight, the player cannot damage him in any way.
In other games
The Big Gate appears in the Battle Cats collaboration event. Morden attempted to bring the Kraken to the present but somehow brought the Battle Cats who dragged him off-screen.
The Big Gate makes its playable debut in the "Next One" Extra Ops. It serves as both a Future Bazooka spawner and as wall from enemy attacks. The Big Gate can be unlocked by purchasing unit parts in the Battle Shop or by completing Standard 8-6 in "Attack!" mode.
Named the Time Slug, it was originally used by Morden in a skirmish before it got destroyed and sent everyone in a parallel universe. Those against the Regular Army joined forces with them to escape to the original universe.
The Time Slug also provides what is called "Returning", where the player's team are transported a few stages back to avoid being overwhelmed. Returning boosts the character's stats, increases the gold regeneration rate, and rewards medals, Gems, and Piece Boxes. The drawback of Returning is that it fully resets the character's levels and the player's gold amount.
|Big Gate: The original.|
|Golden Big Gate: A golden-plated variant of the original. It is still affiliated with the Rebel Army, but the future it comes from is unknown. Rather than deploying future Rebel Army personnel to assist in battle, it instead deploys circular saws to attack enemies, coupled with its own plasma attacks. Appears in Metal Slug Attack.|