Renari, Merchant of Marvels

You may cast Dragon spells and artifact spells as though they had flash.
Choose a Background (You can have a Background as a second commander.)

Skanos Dragonheart

Whenever Skanos Dragonheart attacks, it gets +X/+X until end of turn, where X is the greatest power among other Dragons you control and Dragon cards in your graveyard.
Choose a Background (You can have a Background as a second commander.)

Dragonborn Looter

{1}, {T}: Draw a card, then discard a card.

Psionic Pulse

Counter target noncreature spell. (Then exile this card. You may cast the creature later from exile.)

Sapphire Dragon

Flying
Whenever this creature attacks or blocks, scry 2.

Sapphire Dragon // Psionic Pulse

Sand Augury

Scry 1, then draw a card. (Then exile this card. You may cast the creature later from exile.)

Young Blue Dragon

Young Blue Dragon // Sand Augury

Capsizing Wave

Return target creature to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Sword Coast Serpent

This creature can't be blocked as long as you've cast a noncreature spell this turn.

Sword Coast Serpent // Capsizing Wave

Pseudodragon Familiar

Flying
{2}{U}: Target creature gains flying until end of turn.

Draconic Muralists

When this creature dies, you may search your library for a Dragon card, reveal it, put it into your hand, then shuffle.

Scaled Nurturer

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, you gain 2 life.

Amareth, the Lustrous

Flying
Whenever another permanent you control enters, look at the top card of your library. If it shares a card type with that permanent, you may reveal that card and put it into your hand.

Korlessa, Scale Singer

You may look at the top card of your library any time.
You may cast Dragon spells from the top of your library.

Scale Deflection

Put two +1/+1 counters on target creature and untap it. It gains hexproof until end of turn. (Then exile this card. You may cast the creature later from exile.)

Dread Linnorm

This creature can't be blocked by creatures with power 3 or less.

Dread Linnorm // Scale Deflection

Oceanus Dragon

Flying
When this creature enters, tap target creature an opponent controls. Goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)