The Heroes profiles on the wiki have several problems, which I will attempt to address - one of them is that the feats attributed to
Demigra's Makyouka form (which we have an official translation for now, "Transcended") were only possible because Demigra was significantly amped far beyond his standard level by the Timespace Door, and so should be considered an outlier compared to the regular Dragon Ball Heroes canon. He can still keep the key (the form by itself doesn't seem to be that much more powerful than his earlier transformations, and it has no feats outside of Ultimate Mission X) but only Chamel should scale to it - which admittedly wouldn't really change anything.
It's just a barrier to protect him from Cumber's aura, the same way Goku and Vegeta protected themselves from Lavender's poison in the ToP.