I know the second one is a maykr angel but otherwise I don't know the other 2
I think they are representetive of the main gods of DOOM the red could be davoth, doomguy, the icon of sin the blue could represent vega and the purple could be the khan maykr or switch the last two
You can see some statues of the first one in the walls of that Deag Nilox's thing in Hell on Earth.
Oh it was only one statue
What do you think?