Red Dust of Death:#Carrion#can use Poison. When he does, adjacent opposing characters less than 100 points are dealt 2 damage instead of 1, and adjacent characters of 100 or more points are also given an action token.

Do characters over 100 also take 2 damage.

No, a character 100 points or more will only be dealt the normal 1 damage from Poison, plus they'll be given an action token, per the special power.