"An Endless Duel" is the ninety-ninth episode of the Yu-Gi-Oh! ARC-V anime. It first aired in Japan as a one hour special with episode 100 on April 3, 2016.
Declan and Roger begin their Duel with their pride on the line! Despite Declan's marvelous display of his "D/D" Deck, Roger manages to counter his strategies. However, something unexpected happens to Roger's appearance. Meanwhile, Yuya, Jack and the Lancers reach the Security building, where Declan is.
", which lets him Special Summon a Level 5 or higher Fiend-Type monster from his hand, with its effects negated. It cannot attack and is destroyed during the End Phase. Declan Special Summons "[[D/D/D Wisdom King Chaos Apocalypse (anime)|]]
" via this effect. Since, he used the first effect of "Forbidden Dark Contract" to Special Summon a monster, Declan activates its other effect, which allows him to use the Special Summoned monster as Fusion Material for the Fusion Summon of a Fiend-Type monster, using monsters in his hand or field; however, he will take 2000 damage during each of his Standby Phases. Using this effect, he fuses "Chaos Apocalypse" on field and "D/D Lamia
" in Attack Position. He activates the effect of "Siegfried", which allows him to negate the effects of a Spell/Trap Card on the field until the next Standby Phase. Declan negates "Ancient Gear Magic Shield" ("Ancient Gear Devil": 3000 → 1800 DEF). "Beowulf" attacks and destroys "Ancient Gear Devil", with the effect of "Beowulf" inflicting piercingbattle damage (Jean: 4000 → 2800 LP). "Siegfried" attacks directly (Jean: 2800 → 0 LP).
"Jean" re-joins the Duel, taking the 2000 LP intrusion penalty (Jean: 4000 → 2000).
Turn 3: Jean
The following cards appeared in this episode. Cards in italics debuted here.