Guys, stop trying to put levelling up systems where levelling up systems are not required.
Make your equipment give you all your stats.
Say, all characters have base 10 in all stats, and 20 HP, always. But then their equipment seperates them out.
So take your average, starter game hunter:
Alloy Helm (+2 AC, -1 fire, -1 ice, -1 thunder, +1 dragon, +2 Health.)
Alloy Chestplate (+4 AC, -2 fire, -1 ice, +2 dragon, +3 health)
Alloy vambraces (+1 AC, -1 fire, +1 dragon, +1 Health)
Alloy Faulds (+3 AC, -1 fire, -2 ice, +2 dragon, +3 health)
Alloy Boots (+2 AC, -1 ice, +1 dragon, +1 Health)
Pawn talisman (+10 Oxygen)
Now, if we are going by the same system as the MH games (Once you get to a certain number of points in a skill, that skill gets a new level. In this case, +10 health skill, level one health, which nets you +20 HP)
This equipment set gives them enough points to have get a health boost of +20, and the following defenses:
17 AC (In the games, your defense is always pretty low, so I vote base 5)
-5 Fire (Elemental resistances don't follow the skill system so much.)
Health level 1
Oxygen level 1
How does that example sound? It follows more or less exactly to the source, and looks to be a fairly good way of doing it as well.