Custom Dragons for my campaign

[Cravix]

I am working on a campaign where users have dragon companions. I thought I would post what I have so far for dragon creation to see everyone's opinion

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Syverion Dragon Creation

If you are playing in a Syverion campaign where you have a dragon as a companion to a regular PC character it must be within a step alignment

Each level grants 1d12 HP, +1 base attack, 6 + Int modifier skill points, and saving throws equivalent to a monk of your HD.

Size Chart
Level 1 medium
Level 10 Large
Level 20 Huge

You do not get bonuses for getting size increase

Speed, magic, breath weapon and abilities are based on your age category as defined on the below chart
Juvenile – Level 1
Young Adult – Level 5
Adult – Level 10
Mature Adult – Level 15
Old – Level 20


Breath Weapon (Su)
Using a breath weapon is a standard action. Once a dragon breathes, it can’t breathe again until 1d4 rounds later. If a dragon has more than one type of breath weapon, it still can breathe only once every 1d4 rounds. A blast from a breath weapon always starts at any intersection adjacent to the dragon and extends in a direction of the dragon’s choice, with an area as noted on the table below. If the breath weapon deals damage, creatures caught in the area can attempt Reflex saves to take half damage; the DC depends on the dragon’s age and variety, and is given in each individual entry. Saves against nondamaging breath weapons use the same DC; the kind of saving throw is noted in the variety descriptions. The save DC against a breath weapon is 10 + ½ dragon’s HD + dragon’s Con modifier.
Breath weapons come in two basic shapes, line and cone, whose areas vary with the dragon’s size.
Small
40 ft. 20 ft.
Medium
60 ft. 30 ft.
Large
80 ft. 40 ft.
Huge
100 ft. 50 ft.
Ability score modifiers - Subtract 1 from odd-numbered ability scores from the wyrmling line in the monster description, then subtract ten from each ability score.
For example, the black dragon wyrmling (Str 11, Dex 10, Con 13, Int 8, Wis 11, Cha 8) would have modifiers of Con +2, Int -2 and Cha -2.

Dragons do not take regular classes in my game but can level its racial HD.

Edit 1: I would like to be able to include psionic gem dragons. I found some material here but need it stamped out more.