UPDATE! Newly added to the "AC6 MobileSuit Mod" pack by nmsl2018 AKA Rebellion Silver!!
The latest version of the mod adds Zeta Gundam and Gundam Exia parts to the game aside from all previous available Mobile Suits. In addition, a new Arena match has been added. The new opponent is none other than the Zeta Gundam. Additionally, the Nu Gundam Arena match, along with the Zeta Gundam match, have been shifted to the Analysis section (available only on NG+ and later).

Mod:
"Ac6 MobileSuit Mod " by nmsl2018 AKA Rebellion Silver
https://www.nexusmods.com/armoredcore...
NOTE 1: It is still WIP.

NOTE 2: Before using any mod, BACKUP YOUR SAVE on a usb or somewhere else on your computer, and turn off Steam Cloud Saves. And when you're done with the mod, and wish to play online, delete your current save as it will have all the new data from your use of the mods (especially if you saved custom mobile suit or hybrid Armored Core builds) and restore your backed up save. If you attempt to play online without doing this, you will almost definitely be banned even if you've removed the mod itself.

00:00 - Intro.
00:17 - Zeta Gundam - The Parts
02:14 - Test Run Start.
03:00 - Waver Rider Mode during AB!
04:04 - Beam Rifle
05:41 - Shield (melee weapon + grenade launcher)
07:36 - Beam Saber
08:09 - Kamille's Sp. Attack- WAVE RIDER CRASH!!
08:34 - Beam Saber cont.
09:47 - Hyper Mega Launcher
10:58 - Wave Rider Mode tests (Hard-Lock recommended)
12:21 - VS Trainer AC
14:47 - Arena - VS Nu Gundam
18:13 - New Parts: GN Booster, GN Generator for Exia!!!
18:33 - Arena - VS Zeta Gundam