Lethal Lords of Time: From the 20th to 38th Centuries

In 3780, a nefarious gang leader named Frand Mattar threatened the civil authorities of his era with the destruction to Central City in 1966, should they oppose his henchmen as they robbed financial institutions. The police determined that the  superspeed powers of the Earth-One Flash could unintentionally set off the vibrational bomb placed there by Mattar. One of the law enforcement agents traveled back to the Flash's time, and mentally blocked the hero from resuming his costumed career. Kid Flash and Doctor Mid-Nite of Earth-Two were able to erase this mental block, and the Flash along with his kid sidekick defeated Mattar and his minions whle also disposing of the bomb. This encounter planted a seed of emnity in Mattar's mind, as he sought revenge against both Flash and his fellow heroes of the 20th century.

Six years later in 3786, Mattar returned and reclaimed his criminal organization, Mattar adopted the alias of the Lord of Time, and sent his warriors from both the future and the past back to the 1960s, several months earlier (from Flash's perspective) than when he first met the Scarlet Speedster. Now equipped with a far more diverse array of weaponry, the Time Lord proved a viable threat not just for the Flash but also for the Monarch of Motion's teammate of the Justice League of America. Time and time again, the Lord of Time would match wits with the League, and on one occasion nearly defeated them with his Eternity Brain, until he realized he needed their assistance and that of the Justice Society as well as five historical heroes of ancient times to defeat the mechanized Brain.

In December 1941, the recurring arch-adversary of Earth-Two's Starman known as the Light reappeared, this time utlizing the stolen temporal technology stolen by fellow scientist Professor Grimm. Using a time machine to journey two thousand years into the future, into the 40th century, the Light as "the Unknown" weaponizes an electro-thunderbolt gun to destroy munition plants and other like facilities across America. Starman opposed him, and with his Gravity Rod is able to nuetralize the Unknown's gun, causing the villain to escape back into the future.

Arriving first in 2941, the Light formed a new gang in that era and enlisted their aid in conquering the planet Ultima enabling him to rule his own world. However, he was unaware that the Justice Society of America, including Starman, had arrived at the same time to secure eight parts of the "Bomb Defense Formula" they needed to bring back to 1941 with the intent of protecting the United States from impending war.  Society member the Spectre encountered and defeated the Light, just as the rogue secured the offical garments of Ultima's High Savant ruler for himself. 

Fleeing from the scene, the Light ventured further into the future to recruit the Futurians, bringing them back to 1941 to combat Starman. However, the Astral Avenger discovered that the physically strong Futurians were susceptible to the pollution of the 20th century, and exposed them to it. Defeating his foes' mammoth minions, Starman finally brought the Light to justice... while the Futurians themselves used Grimm's time vessel to travel back to their native time.