Welcome! Have you in the past built fortifications, prepared your base, crafted armor and secured your chests, then noticed that no threat ever shows up? This mod seeks to fix that. If you feel the regular mobs just aren't quite up to the challenge and you want to really test your defenses, then try this out. It also enables some useful recipes and items.
Invasion Mod gives you the ability to initiate an attack on the location of your choosing. The difficulty steadily ramps up and the mobs are designed to deal with base defenses. The behaviour of all invading mobs has been extensively revamped. Most mobs have new abilities and in this beta stage there are some new mobs and substantially more powerful mobs on the way, geared towards new roles.
-Spawn an invasion until a nexus is overwhelmed(most reliable way to test your base and no down time).
-Leave mobs to spawn around a nexus every couple nights if you want to go off and do other things.
-Set mobs to instead spawn randomly at night, like usual mobs but a potentially lot more of them(customisable).
-Items available, like rechargeable traps, to help defend.
Note: the nexus acts as a beacon and GUI for invasions(that's why it's there), but mobs spawning at night don't yet have any way of organising themselves around a player or central point.
The area you set up at will certainly take a bit of a beating (a large beating if you are very stubborn and last a long time), but there is no "massive destruction" or silly unfair mechanics that will randomly destroy all your work. This includes the nexus(it does not damage any blocks). Still, you can back up your map if you want..