Leo is the older twin of Luna and the also one of the Legendary Signers bearing the Heart Mark of the Dragon. He uses a Morphtronic deck whose monster effects change depending on their battle position while also having a lot of equip cards to support them. His ace monster is Power Tool Dragon which would later transform into his Signer Dragon Life Stream Dragon.
How to Unlock
Once you reach Stage 11 in Yu-Gi-Oh! (5D's) World, Leo Unlock Missions appear.
How to get
Twins Together Can be used when your LP is 1000 or below. Add 1 "Double Ripple" from your deck to your hand. This skill can be used once per Duel.
Equipment Restock Can be used when you have 3 or more Equip Spell cards in the Graveyard. 1 random Equip Spell in your Graveyard is added to your hand. Then, shuffle other Equip Spells in your Graveyard into your Deck. This skill can only be used once per Duel.
Level Augmentation Reveal 1 monster in your hand, then target 1 face-up monster on your side of the field; that target's level increases by the Level of the revealed monster. This skill can be used once per Duel.
Equipment Exchange Can be used when your LP is 3000 or below, Place 1 Equip Spell from your hand to the bottom of your deck, and draw 1 card. This skill can be used once per Duel.
Well he didn't recieve his mark until much later so I guess that's one reason he doesn't have it. Besides the Courage and Strength skill gives him Power Tool dragon and it's an easy level up reward to get.
Silent Magician. It's quick and easy, especially if you add in 2-3 copies of The Tricky too
Okay, I just discovered a really weird bug! I battled with Leo against Luna Lv 10 at the gate, fullfilling the mission on Lv 27 (play against Luna). Then the exp counter said +0 and Leo went straight up to Lv 30 but that would have needed at least 5000 or more experience actually, I am not sure. Has someone discovered something similar?