Add protoss as new enemy force. It features a new planet Aiur with new resources and new offensive mechanics. They can optionally spawn on Fulgora.
Mods introducing new content into the game.
New places to build more factories.
New ways to deal with enemies, be it attack or defense.
Changes to enemies or entirely new enemies to deal with.
Map generation and terrain modification.
New Ores and resources as well as machines.
Furnaces, assembling machines, production chains.
Is there any way or command to change the level of enemies from level 10 to level 7?
nope, if you are on level 10, but want to go back to level 7.
The only way to reduce level in that condition is to adjust the max level setting in startup tab.
An alternative way is to adjust the unit properties in startup setting, so that level 10's unit properties are near level 7's.