How did Kiria have Skullion's help? Just because he teleported her away doesn't mean she would've been knocked out if he didn't.
Gray mocking Kiria doesn't mean anything?
Mirajane literally fought Jacob in human form. She oneshotted him with a single punch from BSS. But you seem to believe closing his eyes lowers Jacob's strength so whatever. But are you trying to imply Mira was less serious against Skullion and Madmole than she was against Jacob?
Because the DE's weren't defeated... Unlike your fodder Jacob 
What is base Lucy? She was literally in a Star Dress. Kyria easily overpowered her in their previous fight, by cutting Aqua Metria and the Aquarius Dress. DF Wendy couldn't even touch Kyria. She was toying with them.
About the Laxus part, fair enough. Jacob was not holding back anymore after taking a combo kick from NaLu. Even so, Natsu held back much more. The only attacks he used were his low-end ones in base.He didn't ven want to destroy the guild unlike against Sting two chapters ago. Sting > Jacob.
After stopping holding back, Jacob still could not beat Lucy. He was only going to torture her before Natsu came in period.
"OnE KniFe CoUld CuT oFf LUcy's HeAd", where are you getting such bullshit, Lucy literally rised her arms to protect her head lmfao. Jacob said he would torture her until only her head would be left. Kiria was going to cut off Lucy's right arm had Gemini not took her place.
Aparrently with how we talk about how teleportation affects people’s consciousness that wouldn’t be surprising lol. wasn’t mocking her, more stating what he sees, he is calm and collected. So? Mira fought in human form before. She beat him when he was both nerfed and when she no longer held back, power and stats are based on conscious which has been a thing since the beginning, it has been stated twice that Jacob closing his eyes lowered his strength.
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Yes, because she stated since GMG that she can’t fight seriously when there are people around, but when she is alone, she can fight full power.
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He was simply mad, not out serious, if he did then he wouldn’t bother announcing that he would kill their friends one by one as punishment. Low end? I would doubt he would go low end even when holding back as he stated that Jacob was strong and considering that his strongest attack Savage Flames didn’t even destroy the guild hall when they took out FH Zeref. So size doesn’t really matter. Oh, my bad on the base lucy thing, the sequel has been rather forgettable lately. She dodged, no doubt couldn’t tank it, unlike Dimaria who can both react and tank it in base. Jacob was still holding back, he was still angry, he just wants them to suffer by killing their friends. No, he was still holding back even with Natsu’s arrival, we tortures them till Mavis gives up FH. Which required Natsu to protect her even use his flames to melt the blade, he even said that it would be sad when it was just Lucy’s Head. with where the blade was potioned and now her arms are raised, it definitely was aimed at the neck. So it would for sure have cut off her head. Her head is more vital than her arm.