Profile, Abilities and Weaknesses description is from The Transformers: More Than Meets The Eye, comic series published by Dreamwave Comics in 2003.

BIO 
Monstructor is terror given robotic form. While some Decepticons portray themselves as ruthless death-dealers, Monstructor truly is all that and much more. Those who have survived witnessing Monstructor's formation describe it more like the conjuring of an evil spirit than the combining of a mechanical warrior. Monstructor knows no remorse, except When he misses an opportunity to inflict pain. His very presence drains life, and an aura of palpable dread is his ever-present companion. His utter dedication to destruction and decay goes beyond a mere personality trait, and appears to have no correlation to the six Pretenders who combine to form him.  Monstructor channels an evil far deeper than even the most depraved Decepticon could imagine. Monstructor would prefer never to split into his component parts, allowing him to travel from star to star, destroying all sparks of life. Any Decepticon who has looked into his cold, dead optic sensors knows that Monstructor will gladly start destroying them once the Autobots are no more.

WEAPONS/ABILITIES
Subject. is incredibly strong. His . hands generate a corrosive aura that causes all living things-from the armor of a Transformer to carbon-based life-to decay at. his touch. Subject is able to use his components' thrusters to fly. For unknown reasons, he radiates an energy-draining field all around him that slowly saps power and life itself, transferring it to Subject. If he concentrates, he can focus and magnify the effect, greatly increasing its strength and pace.  He is armed with a powerful solar fission rifle that is powered by star1ight. It absorbs visible light while charging, plunging an area of up to 200 square feet into darkness.

WEAKNESSES
Subjects rifle becomes ineffective if separated from a star-based light source for very long. Use of his powers drains his energy rapidly if he doesn't replenish it. 

Bibliography of significant appearances:
The Pretender Monsters made only one appearance in the G1 continuity:
* Transformers (Marvel) #67 - In this 'alternate reality' story, Galvatron reigns supreme and has left New York City in Ruins.  Interestingly, the story is set in 2009 and depicts a deactivated Rodimus Prime hung between the Twin Towers of the World Trade Center.  

* In later years the team was featured in GIJoe / Transformers Crossover series published by Devils' Due comics.

* The team was also featured in the IDW-verse as the lone combiner.  Apparently, in their view, combiners are an unheard of concept until Monstructor is developed by Jhiaxus...

Other Appearances: