Sorcerous Origin

At 1st level, a sorcerer gains the Sorcerous Origin feature. Here is a special homebrew option for that feature: Draconturtle Ancestor.
Your innate magic comes from the magical power of a Dragonturle that has mingled with your blood or that of your ancestors. Most often, sorcerers with this origin trace their descent back to a mighty sorcerer of ancient times who made a bargain with a Dragonturle. Some of these bloodlines are well established in the world, but most are obscure. Any given sorcerer could be the first of a new bloodline, as a result of a pact or some other exceptional circumstance.

Ocean Spells

1st-level Draconturtle Bloodline feature
You learn additional spells when you reach certain levels in this class, as shown on the Ocean Spells table. Each of these spells counts as a sorcerer spell for you, but it doesn’t count against the number of sorcerer spells you know.

Plague Spells Table

Draconic Bloodline

1st-level Draconturtle Bloodline feature
Your draconic bloodline gives you the following benefits:

• You can speak, read, and write Aquan & Draconic
• You gain a 30ft swim speed
• You can breathe air and water

Dragonturtle's Resilience

1st-level Draconturtle Bloodline feature
You develop a turtle-like shell protecting your body. Your AC equals 10 + Dex + Cha. You gain no benefit from wearing armor, but if you are using a shield, you can apply the shield’s bonus as normal.

Oceanborn

6th-level Draconturtle Bloodline feature
As an Action, you can spend 3 Sorcery Points to cast Water Breathing with additional effects to all creatures it is cast on.

• Creatures gain a 30ft swim speed
• Creatures can speak Aquan & Draconic

Protective Shell

14th-level Draconturtle Bloodline feature
You gain the ability to summon an incorporeal turtle shell to protect your allies. You can create this shell as a bonus action on your turn. When you summon the shell, you pick one ally you can see within 60ft.
The selected ally gains half cover (+2 AC) and resistance to Cold damage.
As a Bonus Action on subsequent turns you move the shell to a different ally you can see within 60ft.
The shell lasts for 1 minute or until you dismiss them as a Bonus Action on your turn. You can use this feature a number of times equal to your PB.

Draconic Potential

18th-level Draconturtle Bloodline feature
You can channel the true nature of your lineage. As an action you can spend 5 sorcery points to draw on this power and assume a Dragonturtle-like form.

• You become a large creature & you type changes to dragon for the duration.
• You grow a tail which you can use to make a Bonus Action melee spell attack with a reach of 10ft, on hit the target takes 1d12 + Cha damage.
• You get a Steam Breath Breath that recharges on a 5 or 6 from a 1d6 at the start of each round.
  You exhale a scalding steam in a 30ft cone. Each creature in that area must make a Constitution saving throw against your Sorcerer spell save DC, taking 6d6 Fire damage & 6d6 Cold damage on a failed save, or half as much damage on a successful one.