Honestly I thought I'd throw out some more Captain Planet while I was at it. Character analysis Wheeler! This won't be deep but It should give a bit of insight.
Wheeler is the brash and hot headed member of Captain Planet. The fact that he is American and has the fire ring are no small coincidence. Fire is a powerful ability but has the most ability to harm another and backlash as well, a symbol of the US's ability and how they should handle their great power.
As well Wheeler is supposed to be the character meant to be the everyman and to ask all the questions we may have. In a bad episode wheeler seems stupid and often abusive to the other members of his team, he can be quite a bully. In a good episode Wheeler is quick thinking and is great with dealing with problems involving people, for example he was the only member to know how to trick people into fastening ropes too lightly and if the team needs to pick a lock he is the one to do so.
Though the thing to remember is that each member of Gaia's team is there for a reason. Wheeler's ability that no other member has is that he has the ability to connect with people. While one could argue that Ma-Ti being heart also has the ability, his is more accurately that he has the ability to melt any heart with his kindness. Wheeler however is the only member with the empathy and blunt honesty, he rarely holds back his oppinion, to connect with those around him, as well he is the closest member to being a real person as all the members are too dutyful or too good-hearted to really understand. As well the other members of the team automatically know what is right but wheeler is the only one who has to learn the significance, he would be the only one who would be able to explain why something is significant to people who don't already know.
In essence Wheeler is the second heart of the team. In a episode where wheeler never joined the team the other members simply didn't have the heart to join together.