Hello I'm Kingpudding I felt the need to give the underplayed characters some recognition of what they are good and bad at yet no one notices them. I will add to this list as I go. Its a basic starter thus far.

Hecarim: He is our favorite little pony. His passive is very unique that gives part of his speed to his attack damage. hecarim is hardly played I believe due to his squishiness early game. But the Pros of him are a great CC ult, a possible jungler/ top lane champ.

Heimerdinger: The underplayed and misunderstood inventor. People who don't play him often have the thought "it's all about the turrets man". Then they suck because they can't harass or farm well due to the turrets. His pro's are blind/stun/slow spells and can heal turrets and people.

Karma: She is sad to say a terrible champ. I have tried time and time again to make her useful but she just seems to fall flat on her face. She has a purposed to be underplayed and should be left that way in opinion.

Poppy: poppy is such an interesting character. I haven't had the pleasure to play her often. Her Ultimate is her best quality and makes her invincible for a short amount of time except for one target which can be chosen.

Rumble : I personally love Rumble. He is very fun and is a really great kiter. he is my favorite champ to lane against Garen my archenemy. He has low cooldowns on his abillites and he doesn't use mana. And each of his spells have a range component in them that really help. And his ultimate The Equalizer is great for teamfights.

Sejuani: I really think Sej has great potential and should be played more often. Her ganks are great and she is useful late game with her ultimate move.

Skarner: He is very situational. He takes time to master and his ultimate is very strong. Skarner is similar to Warwick in some cases as his jungling is really best post level 6 with his ultimate. But he is very tanky if played by good summoner.

Trundle: Our loveable troll friend has long been forgotten by summoners but kept in Co-op VS AI games. Trundle is a string jungler and can really benefit a team late game with his Q that drains attack damage. He is one of the strongest territory fighters due to his contaminate zone and his Pillar of Filth.

Urgot: Our spider/human/crab thing is rarely seen and played well. Urgot is a great adc and top lane character due to his range and abillites. his Q Acid Hunter works with his Noxian Corrosive Charge to make a homing attack which is his main form of damage.

Viktor: He is by far one of my favorite underplayed champs. People say his augments aren't helpful for season 3. But he is really strong as a character. His W gives you crowd control and his ultimate Chaos Storm is great for it too.

Xerath: He is simply a long range mortar canon. He is a decent champ but they need to buff his AP scaling because of the low damage of his spells.

Udyr: Ok SO he is a very "unique" champion as he can level any of his abilites up first. He is a jungler mainly but can also be played top, or bot.<iframe width="560" height="315" src="http://www.youtube.com/embed/YlTwyA1SrVM?rel=0" frameborder="0" allowfullscreen></iframe>

Sion: So sion is an interesting character as his main goal is to farm. He gains tons of health from one of his spells but can also be played AP as well as heavy AD

In opinion the champs that have the best potential to come back are

viktor: As a mid character his ability to fight and push is wonderful and he can easily harass his opponents without taking much damage. Then late game his W gives your team a Crowd Control and his Chaos Storm adds a lot of damage to the fight. Viktors augments also act like a scaling ability power rune that can be upgraded into one of three ways to best suit your situation.

rumble

sejuani

They all have a great set of skills and are compatible with a lot of different teams.

Urgot

Skarner

Hecarim

These three have a decent chance of coming back if people learn to play them.

Karma

It's karma I hate to bash on champs and sorry to all the Karma sympathizers out there but she is really useless. Her skills seems really good but fall off before she can get to late game. And the mantra perk is interesting but it takes so much to master some of her skills.