Meliodas vs. Ban is a battle between Dragon's Sin of Wrath, Meliodas and Fox's Sin of Greed, Ban of the Seven Deadly Sins.
During the infiltration of the Liones Kingdom, Ban snuck into the castle where he easily evaded a patrol of Holy Knights and interrogated an unlucky Holy Knight whom he used Snatch to take his teeth to find the location of the Horn of Cernunnos successfully. After encountering Hawk in the underground area where the Horn is, a voice supposedly from the Goddess Clan spoke to Fox's Sin of Greed and agreed to fulfill his wish of resurrecting Elaine from the dead if he kills Meliodas for them allegedly claimed that the captain of the Seven Deadly Sins is one of the Demon Clan, much to Ban's surprise.
During the chaotic battles between the Holy Knights and the New Generation-turned-Demon hybrids, Ban appears with his nun-chunks before Meliodas who was wounded earlier by Hendrickson's power "Acid" along with Hawk. On the other hand, Meliodas was pleased to see Ban and tells him that they have to rescue Elizabeth again but suddenly noticed his best friend's non-responsiveness and asked if he's gonna say something.
Ban then told captain that he loved him as a buddy while utilizing his Snatch and nun-chunks to rip off Meliodas' right arm and asked him to hold still so he can kill him as painlessly as possible. Then Meliodas retaliated by striking Ban directly so he can get his arm back and reattach it with the Demon Mark activated by will. The Fox's Sin of Greed notices this and asked his captain if he's part of the Demon Clan or not and took Meliodas' silence as a yes.
Meliodas wasn't amused of Ban's intentions to fight him at all in times of dire situation now as he and Ban made quick clashes with each other. Gaining the upper-hand, Ban reveals to Meliodas that he received orders from the Goddess Clan to kill him so Elaine will come back to life as he sent Meliodas flying into the castle wall hard and pinned him down quickly before the latter even get up and counterattacked.
Hawk tried to discourage Ban into cease fighting or he'll break their friendship if he kills Meliodas but was immediately silenced by the Fox's Sin of Greed. Deactivating the Demon Mark, Meliodas understood Ban's intentions and would have done the same if he were in his shoes, allowed his best friend to kill him off now if he wants to be reunited with Elaine, much to Ban's delight.
Ready to kill Meliodas, Ban was about to impale him with the sharp end of the nun-chunks, while telling Elaine to wait for him and then suddenly Meliodas headbutted Ban hard and sent him flying into the debris. Recovering from an unexpected impact, Ban angrily berated his captain for ruining the chance of getting Elaine back but Meliodas defended his intentions that while he allowed his friend to get what he wished, he cannot allow himself to leave someone he cared about. Hawk joined in and managed to bring Ban's senses back, then Meliodas exerted his authority as the captain of the Seven Deadly Sins to order Ban to do his job he is obliged to fulfill as a member of the Seven Deadly Sins to save the kingdom and settle such petty matter later, much to Ban's reluctant compliance.
Ban reluctantly agreed to hold off the matter between him and Meliodas for now and focus on saving the kingdom of Liones from Hendrickson and the Demon hybrids and the rescue of Elizabeth again.