Sorry old man I am just trying to get it clear with you that statements such as "pure energy" are meaningless in science since we do not know what energy itself actually is.It is an abstract value that we measure in given situations that remain the same as dictated by the law of conservation of energy.
It would likely be that they are writing to the general public and try to write to that audience rather than be more accurate and confuse the issue. Also they may not be specialists in a given field but rather science writers with a general knowledge of the field.
Work involves transfer of energy. Energy can be unavailable for work {hence entropy}.When something is in thermodynamic equilibrium with its surroundings then energy will not flow or do work.
alien with a technology so advance that it generates some kind of field to literally trap energy