I also think that there are more reasons to believe that DK Zel has the magic immunity rather than not. The reason why I'm saying that he's probably so weakened that he can't use it right now is because it is what actually makes more sense, IMO. Let me explain, if Elizabeth's magic on a human body was since the start so powerful that can bypass the DK's magic (something that not even Ludo or Mael's Greatest Sun could do), then:
I mean... there's no explanation as to why the Demon King can't use his magic immunity in Zeldris body when his son can use it without being possessed.
Plus, the Demon King commented that Elizabeth's magic attack wasn't capable of killing the ''Demon King'' which reflects how Zeldris has commented on multiple occasions that magical attacks will do nothing to him.
Why have such arrogance against Elizabeth's attack unless he had his immunity active? I'm sure he underestimated her, but at the same time he should be aware that she isn't entirely weak.
- Why she couldn't do anything when Meliodas started to revert into his original self? It was highly implied that had Merlin deactivated the Perfect Cube and not have been for Escanor, AM Mel would have killed all of them. Mind you, AM Mel was only 142K at that time.
Plot? Would you rather see Escanor fight Meliodas and turn into ''The One'' to finish him or have Elizabeth solo him without much difficulty? Even as a Elizabeth fan, I'd rather see a tough battle than a one-sided domination.
Plus, you could argue that Elizabeth didn't want to hurt Meliodas and showed at a later moment that she was perfectly comfortable in being inside a perfect cube with him, when he might've woken up when she was holding him.
The lovers are very cautious about hurting each other, Meliodas forced Elizabeth into some situations but never directly hurt her to do so and allowed Elizabeth to slap him. Elizabeth practically begged Merlin to let her heal him since she was worried about his health - So I'd say one reason why Elizabeth didn't jump in the cube with Meliodas was because she didn't want to hurt him?
- Why Estarossa could broke free of her Ark casually using darkness?
Multiple reasons in my opinion:
-Estarossa is actually Mael, a Goddess who has a natural resistance against the light element, thus helping him break out of the ark easier along with the force of his darkness.
-Elizabeth was more concerned about protecting Derieri, since she didn't want Estarossa to collect her commandment for Meliodas. I think this is supported by how Elizabeth simply moved him away and crashed him into a mountain rather than toss him around (like with the DK) or explode the ark for larger damage. She simply tossed him away and didn't care for what happened? If she wanted really hurt him, why not explode the ark? Why not do an ark blast or a more offensive move by nature?
-Plot? Or because she had a subtle hint about who Estarossa is (she noted how ''she knew him'' before this moment) and thus didn't want to hurt him.
-Maybe she just wanted to hand him over to the AA's? Let her not fight (as she wants) and let them have their ''revenge''?
TL.DR - Elizabeth didn't want to actually hurt/kill him.
- Why she had to be saved from 3C Estarossa? You would think that with that level of magic, she at the very least would have been able to escape for herself, but it wasn't the case at all.
Plot really. Plus, with the entire situation with Estarossa taking her to Heaven's Theatre she was curious about who he was and wanted to recruit him to fight against Meliodas. Unconsciously, she felt like he was Mael or someone she knew and thus didn't want to fight off/abandon him.
With Meliodas, she did fight him off and run away, but with Estarossa there was an underlying feeling of her wanting to know who he was.
- Why she went pale with only sensing 4C Mael's mere presence?
I don't know really. If you wanted me to drag any excuse out of the book, then I'd say:
-She wanted everyone to run because they could be killed + she didn't want Mael to be killed by them.
-To hype Mael, for King's power-up.
- Why didn't she try anything against DK Mel and her only contribution during the fight was her cheering Mel pretty much? Why her Ark didn't do anything to a half-dead DK Mel, who broke it instantly?
Wasn't everyone trying to protect her? Wrapping her in bubble wrap, inside a perfect cube and not even give her a chance to fight? Plus, this time the DK wasn't standing still and letting her fire ark at him - he was going to attack her with his tentacles.
Human Elizabeth being powerful enough to actually mock DK Zel, bypass his magic immunity and hurt him does make even less sense than saying that DK Zel is weakened and somehow can't use his magic immunity.
Disagree, Nakaba's consistency with Elizabeth's power (I.E making her strong/weak for the plot) makes more sense than the Demon King being incapable of using the very same power his son can.
I don't doubt Eli is powerful, I always thought she was and I've defended her way before the last chapters came, but I think we should wait for more feats before getting too carried away with this feat of her seemingly bypassing the DK's magic.
Perhaps.
The biggest issue with Elizabeth is Nakaba's consistency. For one moment she'll be the damsel in distress to move the plot forward and in other situations she'll fodderize/embarrass somebody without much issue even though that contradicts earlier scenes.