WARNING: The following contains spoilers for One Piece Chapters #997 by Eiichiro Oda, Stephen Paul and Vanessa Satone, available in English now from Viz Media.
For many One Piece fans, Tony Tony Chopper has been relegated to the cute mascot since the time skip, not really contributing much in the way of fighting or support. However, since the beginning of the Wano Arc, he's been given a chance to shine as the Straw Hats' doctor. He's become a major player in the arc, having developed an antidote to the Ice Oni virus in the middle of a war zone. This is a major step for the character.
When originally introduced to the story, Chopper was a reindeer who had eaten the Hito-Hito no Mi and lived on Drum Island. Originally ostracized from his herd for having a blue nose, then for eating the Devil Fruit, he was eventually taken in by Dr. Hiriluk, who was dubious at best with the administration of "cures" and medical practices. It was Dr. Hiriluk that instilled the idea that there was no disease that didn't have a cure into Chopper's mind. When the doctor was dying of an illness, Chopper went out searching for a mushroom to cure said illness, becoming wounded in the process. The mushroom was poisonous, but Hiriluk still ate it because he didn't want Chopper to become disheartened. He then later took his own life so that Chopper wouldn't blame himself for the doctor's death. After this, Chopper was taken in by Doctor Kureha and trained under her for six years before joining the Straw Hats.
This brings us back to the importance of Chopper's role in the Wano Arc right now. His ability to create a cure for the Ice Oni virus in Chapter #997 mirrors the inability he had to save Dr. Hiriluk and serves as a form of vital character development for him. Not only that, but he was able to create the cure while suffering from the virus himself and while in the midst of a huge battle. He was able to analyze the only antidote available and deduce that exposing victims to heat could hold the virus off while he mass-produced the antidote. Doing this showed a great amount of confidence in his own abilities, which is rare for the reindeer as he and Usopp are usually relegated to comic relief. While he's usually the one to help the others when they become injured, it's rare to see his medical abilities and prowess used beyond patching Luffy up after a fight.
While the other Straw Hats have had major character arcs and development, Chopper hasn't really had the same chance up for a long time -- until this point. The fact that he was able to cure the Ice Oni virus opens up Chopper to have more development as the story continues. We hope that this won't be a one time deal, and that Chopper continues to have his time in the spotlight more often.
