You can't give in to the aliens just yet! Instead, call upon demonic powers from Hell to consume their souls! Though the effects on your own soul may prove unfavorable...

INSTRUCTIONS:

• Beat the boss at the right-most end of the map
• You can use siphon soul [right click] on enemies that are low enough health and are in your siphon range (the blue circle)
• There is a window of time where siphon soul can be used again after obtaining a soul
• Each consecutive siphon soul increases the ability's range temporarily

Everything made by me (apart from the window-breaking sound from the internet)