Should have been a contender: Issue 9

This one is pretty short.  He's one of the longest running Academy members, being a trainee was Dawnstar was there.  We all know him: Jedidiah Rikane, aka Power Boy.

Jed's power was original termed as a condensed molecular structure, granting him super strength and a degree of durability, though nothing on the level of Kryptonian invulnerability. It's a power that would be tough to get into membership given how many members possessed super-strength.

He was from Earth but we never got an origin story as to how he received his powers.   Nevertheless, he made several appearances over the years, mostly cameos.  Sometimes showing some true combat ability, sometimes not..  He was killed off during the 5YL timeline and wasn't seen in either of the other two Legions.  His character returned in the Legion Academy stories in Adventure Comics.  Here, he changed greatly.  The first notable change was the while he dated Lamprey in the Academy during the Levitz/Giffen years, now he may be considered bisexual, as he began a relationship with Gravity Kid. 

Secondly, his appearance, while muscular seemed slightly less bulky.  Thirdly, his power is referred to as personal density control, indicating that he could increase his density at will, and decrease his density to the point of becoming intangible.  He was like the Vision or Jesse from Mutant X if anyone remembers that show. 

As a side note, can I say that I enjoy the use of black over blue in his costume.  It helps tone down the garishness of having purple skin with his ginger hair

With these expanded powers, he obviously would be much more useful, being able to handle both espionage and be in the thick of combat.  If Tinya and Jo ever decided to leave the Legion, he makes up for both their absences . Even if they were not gone, he would still remain a unique member of the Legion. How many Legionnaires powers can be used in place of others?  Reep or Yera instead of Vi anyone?

Personality-wise he was a bit of a meathead. Levitz, his creator, seemed to favor giving people with super-strength a lack of intelligence.  I doubt Levitz ever intended to give him much respect as a character.  I get it, not everyone can be a Legionnaire, but there is also something to be said for having characters with more unique abilities.

Unfortunately, the Retroboot was not kind to Power Boy.  Jed graduated from the Academy but was not offered Legion membership.  He, Lamprey, Crystal Kid and Nightwind were shoveled off to the SP or something else.  Long term Legion fans probably wanted to see these characters again and become members, instead of Comet Queen, Chemical Kid and the rest. I don't think Levitz ever really had an interest in developing those characters. 

Now, he may be relegated to Limbo again as there is no Academy in the Bendis-boot nor has he made an appearance yet as a tertiary character.  I think it is a shame. Bisexual characters are few.  His powers were unique enough to make him useful.  

Universe Building: the Legion Academy

The Legion Academy, at one point known as the UP Militia Academy and the Legion Cadet program, was a training school for the Legion of Superheroes.  The wikipedia entry on it makes me chuckle:

Training there may be deficient to some degree, however, as Chemical King, Karate Kid II and Magnetic Kid have all died in the line of battle, though as two of those were selfless sacrifices made to save others, they clearly teach heroism quite well.

LOL.  Initially, it is not clear who was in charge of the training at the Academy.  Wildfire does appear to be heavily involved in it after he becomes a member, but that is after Timber Wolf and Chemical King join.  We see later that Duo Damsel and Bouncing Boy later become instructors, which was actually a pretty good way for Levitz to keep their fans happy.  In the Retroboot, however, Levitz demotes Night Girl from full membership to Academy instructor (and presumably reserve status).