Those are chemical elements, Kim. The elements that were asked about are stuff like Fire, Ice, Thunder, that sort of thing.
And some worlds have a combination system (like Water+Wind=Ice); I believe Dragon Riders Continuity Yami that Shane started on 27 May works like that?
To keep things on-topic:
PK, what would your Final Smash be like if you appeared in Super Smash Bros?
EDIT: 40 posts. Two cheers.