Jack is the Turbo Duel Champion and one of the Legendary Signers bearing the Wings Mark of the Dragon with his signer dragon/ace card being the Red Dragon Archfiend. He is one of Yusei's oldest and closest friends and would help him in his battles throughout the series.
How to Unlock
How to get
Assault Exchange Shuffle 1 "/Assault Mode" card from your hand into the Deck. Add 1 "Assault Mode Activate" from your deck to your hand, This skill can be used once per turn.
Majestic Light Shuffle 1 Tuner monster from your hand into your deck to summon Majestic Dragon from your deck. This skill can be used once per turn.
Red Dragon Archfiend might be the weakest of the Signer Dragons in Duel Links. (Black-Winged Dragon easily takes that crown in the TCG/OCG, but with the lower LP and potentially fewer Synchros, it could beat RDA.)
Not exactly. With Zane we had to wait almost a year from last September until he had his unlock event in late July. He was also featured in a lot of events in between. And even when they were going to release him, it was still treated like some big secret. Remember "GX character unlock event" on here? They took it too far.