EVT

EVT is a binary event format used by Atlus in Persona 5. It is used to setup cameras, objects, animations, dialog and more in cutscenes where you can't control the character. In other circumstances where dialog is shown but you still briefly control the character, those scenes are likely using BF instead.

Location
Persona 5's EVTs can be found in the PAC files in data.cpk\event.

EVTEditor
EVTEditor is a program by ShrineFox based on TGE's EvtTool, featuring a GUI with a timeline. You can open an event PAK or EVT with it to add, modify and reschedule commands and objects. If the event PAK contains a BMD, you can edit the decompiled text on the fly. Download it here.

EvtTool
EvtTool is a program by TGE that dumps the contents of an EVT, ECS or LSD binary to an editable JSON file, which can be opened with a text editor such as Notepad++. By dragging an EVT onto the EXE, a JSON will be generated (and vice versa). You can download EvtTool here.

Alternatively you can use the program through the commandline by passing in the file path to either an EVT or a JSON file (in case you want to batch the conversion, for example).

P5_EVT_ECS.bt
A binary template for 010 Editor can be used to study the structure of an EVT/ECS file while hex editing. Download that here.

Format
The beginning of an EVT file is comprised of event parameters (such as ids, duration), followed by object definitions (object ID, type, resource IDs, animation IDs). After those, commands make use of the object ids to set positions, play animations, execute script procedures and show messages. Each command has its own specific parameters and a short descriptor (e.g. MSD_).

Below are a list of all commands and their functions (to the best of our knowledge).