The Lord of Apokolips, Darkseid is a powerful, god-like being who seeks to conquer Earth and ultimately obtain power over all life.
Superman and Jimmy Olsen first encounter Darkseid through the agency of his minions, including Morgan Edge II, in November 1970 when they battle the Mountain of Judgement alongside the Newsboy Legion (SPJO No. 134: "The Mountain of Judgement").
In January 1971, Darkseid's servant Simyan notes that he is "stern, but he rewards his loyal and efficient servitors." Darkseid's own words, however, betray a personality that is less sanguine:
Yes but who can deny the power of the other side? Death can eclipse life! A great lie can smash truth! And the answer to a finely disciplined Superman is ... a chaotic fury of a thing --an uncontrollable organic murder machine!
(SPJO No. 135: "The Evil Factory")
The Omega Effect, manifesting itself in the form of beams from his eyes, is Darkseid's most fearsome power. It is capable of producing anything from gentle warmth to matter-annihilating heat.
These eye-beams are guided by Darkseid's mind toward his desired target and are capable of amazingly catastrophic destruction. They can also teleport a foe through time or space and even bring back beings that were previously destroyed by the Omega Effect.