King vs. Helbram: Rematch (Kingdom Infiltration arc)

King vs. Helbram: Rematch (Kingdom Infiltration arc) is a battle between King of the Seven Deadly Sins and Helbram of the Holy Knights.

Prologue
After Hendrickson used the Black Mark to recover from his defeat, the druid used one of his people's forbidden technique Enslavement of the Dead to revive Helbram back from the dead who was recently killed by the Grizzly's Sin of Sloth in a battle between powerful fairies in the kingdom's capital.

Battle
Taking advantage of the chaos caused by the berserk New Generation/Demon hybrids, Hendrickson intends to recapture Elizabeth Liones to proceed with the ritual to break the Coffin of Eternal Darkness sealing the Demon Clan and start the Holy War. King attempts to ambush the Great Holy Knight from behind but the latter had Helbram attack his best friend much to the fairy's shock. Explaining how he revived the fairy two times already but because of that, Helbram became nothing more than a shell of his former self, much to King's (and Diane's) grief which delighted Hendrickson enjoying the sight of the Fairy King's grief over his best friend's cruel fate as the undead fairy charged to attack.

Clashing with their respective weapons at each other, King frantically begged Helbram to stop but the latter only responds with an erratic regressed words and continued battling relentlessly. Still trading blows, King pleads Helbram to stop, not wanting to hurt him anymore. Helbram tries to say something to King while about to perform an attack only to be struck by a large rock thrown by Ban, much to King's displeasure.

After Ban reminds King of his duty as the member of the Seven Deadly Sins, Helbram managed to control himself for a little while, begs his best friend to put him out of his misery for good, much to King's grief over the fact of killing his best friend again. When King refuses to kill him again, an angered Helbram tells him that they're not friends anymore much to King's shock. Hesitantly, a tearful King summoned Form Four: Sunflower of Chastiefol and unleashed a massive barrage at Helbram who smiles in relief to be freed from a cruel fate as the undead fairy's body vaporized, leaving the old helm he wore behind.

Aftermath
After finishing Helbram off for good to finally give him peace in the afterlife, King picked up the old helm and wonders if he had been best friends with him in the end. Later on, King joined with his comrades and battled where he sent forth a swarm of kunai-like projectiles of Chastiefol all over the Great Holy Knight after switching places with Meliodas who baited Hendrickson for the attack, taunting the druid to at least three times for him otherwise Helbram would be mad at King if Hendrickson didn't.