I agree with Dave that an AWES including the figure 5 could be interesting. Some discussion is initiated on Completing Mothra, including variants.
As this system should be adjustable (within a ring eg.) with respect to the wind direction, it looks to be particularly designed for a very large kite. It should be reversible if possible, that because of the forth and back move. Dave mentioned Dave Culp’s OL single skin kite.
Some remark: the length of the trajectory should be the same as the distance between the two pulleys-generators, that in order to assure an alternate move without stopping generation.
Some question: how the kite can be positioned and bridled?