While I did find reports on the card already, I did not find this.
In a battle with a friend, he attempted to use Verdant Wind's effect of adding energy to benched Pokemon (From Verizon EX #9 I believe.) on said Sigilyph.
Expectantly, it didn't work. Unexpectedly, it decided to discard itself.
While hilarious, that's probably not what it's supposed to be doing.
This is probably worth some looking around to see if other Safeguard-like cards do this as well.
Apologies if something like this is already reported.