None.
I think this was mentioned some time ago in earlier threads/posts, you CAN'T, I repeat, CAN'T change the terrain with an Extended Unit Death Trigger. 

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Ultraviolet -- "Not many people know this, but I actually got the idea for my mustache after seeing the end of a paintbrush for the first time." 
Ultraviolet -- "often was always pretty cool" 60% of the time, it works every time 
NudeRaider -- The visuals are good, the animation is terrible: the movement is off, the impacts in battle scenes have zero weight to it, the lip sync is right up uncanny valley. But yeah, considering what it is it's pretty good overall.
NudeRaider -- Nekron