Turns out, there are more than one games that provide you to customize your own factions.
Here is the list of games with Pros and Cons:
Empire Earth + Art of the Conquest
Pros:
- Simple and quick real-time strategy game.
- Quick and easy civilization editor that gives upgrades to units and structures.
- Not-really hard to make the triggers at the editor.
- Allows you to make quick and easy custom scenario and campaign. You can make stories with it.
Cons:
- All the units are the same for every civilization. Custom units are only available on campaigns, such as Germany Soldiers.
- Renaming and modifying units only limited to 99.
- All research mostly for Christians and apply to any non-Christian worshipping structures (like Mosque) which are, kinda weird for me to play.
Cosmoteer (The Forum)
Pros
- Build and command game.
- Bazillions of ship design to make.
- Tons of mods to load (if your pc is strong enough).
- A lot of factions to make.
- Create your own mods to enhance the roleplays.
- Able to create the personal faction mod.
- Many stories to make with it.
Cons
- Top-down 2D sprite game
- Only space-based
- No scenario and campaign editor.
- Only human crew.
- Need a bit understanding of modding.
Galactic Civilizations III
Pros
- Successful custom faction-based strategy game.
- Customize your own civilizations and their interfaces.
- 3D realistic
- 3D spaceship editor
- Can create mods.
Cons
- Complex and expensive game.
- Space-based
- Hard to make the stories with the scenario and campaign editor.
- Need to study realism illustration to make a decent civilization.
Minecraft
Pros
- Sandbox game
- Build any structure style for the faction.
- Can play with mods.
- Create custom machines with redstone.
Cons
- 3D blocky game
- One faction stats are different on every server.
- Play as a character instead of commander.
- Mostly used to raid items instead of roleplaying that slightly close related to politics and ideology.
StarMade
Pros
- 9 Quadrillion of galaxies to visit.
- Create the design style for the faction.
- Territory conquest system.
Cons
- 3D blocky game
- Space-based
- Play as a character instead of commander.
- Cannot make scenarios and campaigns.
My own planned game
Pros
- Simple and easy scenario and campaign editor, with a pretty good cutscene and trigger editor.
- Downloadable user-made factions.
- Create custom units, structures, research, upgrades, sprites, weapons, etc.
- Applies to any genre (space, fantasy, modern, medieval, ancient, many more).
- Applies to any terrain (space, land, water, sky, underground, many more).
- Both mana and energy stats are welcome.
Cons
- SHP sprite game, nothing so realistic.
- Only 2 economy stats (currency and resource).
- Need to learn how to make a decent SHP sprite.
Forged Battalion
Pros:
- 3D real-time strategy game.
- Cheap (IDR 108.990)
- Faction Customization tool with the unit editor and overview.
- Apply any weapon to a unit.
- Can create a new unit
Cons:
- Only modern-based.
- No naval units.
- No structure editor.
- Limited models, research, and weapon for the units.
Everything is based on my opinion and information I collected.
If you have other game to make your factions, let me know.
After the high school graduation, I would like to study coding after I can do some illustrations.