I think I've got the after death dialogue figured out.
Make an event with a name like ev::AfterDeath
Event type is 00 00 00 00
Within this event make a check for a flag and then end it with 01 48 instead of 01 21.
This goes to a different event that does what you want to be done.
You'll also want to make another check before this or else the next event will play after every action made. The game uses 4D for this type of check. Don't know what the difference is between 4D and 4C. There's also a 32 before the 4D. Not sure what that 32 means as well.
An example of the check would be
1D [Flag] 47 [ev::FlagGet] 01 32 4D
Second Event:
Event type is 14 06 01 00
Sub header for this event goes:
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
FF FF FF FF
[Pointer to the name of the event with the check]
Then do whatever you want here.
There's still things I don't get and will probably need more testing.
Here's an edit I did of Marth's Amiibo battle that triggers some text after initiating a fight with Marth.