Identity Crisis for Joseph Meach

Joseph Meach a.k.a. The Composite Super man first appeared in World's Finest Comics #142 in 1964.

In terms of abilities and raw power, the Joseph Meach version of Composite Superman was one of the most powerful enemies Superman and Batman ever faced. He had all of Superman's powers, but to a far greater degree, derived from Supergirl and the similarly-powered Mon-El and Ultra Boy. The Composite Superman also possessed numerous special powers, derived from various Legion members:

The ability to grow to giant size (Colossal Boy)
The ability to shrink (Shrinking Violet)
The ability to divide into 3 people (Triplicate Girl)
The ability to fire lightning bolts (Lightning Lad)
The ability to generate heat and light (Sun Boy)
The ability to make things super-lightweight (Light Lass)
The ability to make things super-heavy (Star Boy)
The ability to consume absolutely anything (Matter-Eater Lad)
The ability to turn invisible (Invisible Kid)
The ability to inflate into a large ball (Bouncing Boy)
The ability to stretch any part of his body (Elastic Lad)
The ability to shapeshift (Chameleon Boy)
Telepathy (Saturn Girl)
12th level intelligence (Brainiac 5)
Magnetic powers (Cosmic Boy)
X-ray vision that could see through anything, even lead (Ultra Boy)
The ability to transmute elements (Element Lad)
The ability to phase through solid matter (Phantom Girl)