There is are only two ways for a player's level to be decreased.
The first is through a rollback, which is a punishment of botting if you are caught.
The second is that Jagex Moderators can modify their levels at will for testing purposes, however it is highly unlikely one would modify another player's stats.
There are players with 9 HP (now known as constitution), however rare that is - In runescape classic the starting EXP was different, while you would start at 10 in classic, once Runescape 2 started people with characters from classic found they had a hp level of 9 if they hadn't earned any experience in it.
It is very rare to find 9 HP characters.
A player's fishing level can only decrease through a Roll Back if they are caught botting as it is against the Rules of Runescape.
You can fight all levels in Runescape. You can fight all levels in Runescape.
It will decrease.
Keep training.
decrease.
no
Tulou is not a monster in RuneScape. Thus, the amount of levels it has cannot be determined.
If you read the Runescape skills manual you wouldn't ave had to ask this question.
There are not any lvl 29 dragons on runescape, dragons are levels 42 to 400.
The atmospheric temperature will decrease
go to combat or levels menu
No.