PSA: ExTools is currently unstable when saving certain levels (exanima01, arenahub, and maybe others), but it is absolutely capable of creating new levels from scratch.
The Council of Conservers modding discord server:   / discord  
ExTools: https://gitlab.com/C0RUS/extools//tr...
Installation Guide:    • Exanima "ExTools" Level Editor  Inst...  

0:00 Preface
0:27 Loading a level
1:09 Navigating Unity
1:42 Node type: Libnodes
2:25 Node type: Omni lights
3:13 Node type: Objects
4:09 Navigating the Objects Databases
5:57 Object Classes Preface
6:19 "Thing" Class
6:30 "Object" Class
7:11 "Procedural Weapons" Class
8:42 "Apparel" Class
11:47 "Container" Class
12:41 "Droptable" Class
14:03 "Trigger"/Zones Class
14:38 "Door" Class
15:17 "Operative" Class and Trigger Types
15:34 Item
17:12 Special
17:35 Effect
18:00 Brazier
18:13 Miscellaneous
19:39 Levers, Buttons, and Mechanisms
22:09 Characters
23:26 Tilemap Editing
25:02 Ending

This is a guide on how to edit levels using ExTools, an unofficial level editor built for Exanima built using the Unity Engine. If this is your first time seeing the editor and you would like to use it yourself, feel free to follow the steps in my previous video where I covered the installation process.

It is worth mentioning that ExTools is currently under active development, so while some menus and UI elements may changes in the future, the data covered in this video should still be relevant for any newcomers interested in modding Exanima.