Re read the chapter Pride against wrath. Look at Escanor : it's like they never faced before. If he lost with The One do you really think he will face Meliodas like this with a weaker version of him? Plus in the previous chapter he said what an interessting transformation. It means he never saw...
I'm sorry but this is beyond stupid. The One is actually facing the Dk. The Dk presence can destroy Britannia. If Meliodas>>>The One than at this moment he was stronger than the Dk. It means Britannia should be destroyed atm. This Is so dumb and stupid. All this is to put Meliodas at the top again.