...but I personally oppose blending "Sailor Moon" or any other anime with sacred and cultural symbols.
You are a bit late, since the entire series is blended already with various symbols and references from Greek mythology, Shinto, Christianity, Buddhism, and what not.
You didn't get my point. It is okay that the story references all those religions. I am a Buddhist practitioner myself, and I love that Sailor Moon references Buddhism.
What I oppose is creating a Sailor Moon-inspired dream catcher. A dream catcher is a sacred and cultural symbol for Native Americans. Creating a dream catcher to promote Sailor Moon feels like cultural appropriation. It'd be the same as creating crucifixes featuring the image of Usagi, and not Jesus.
That being said, the artist who created those is extraordinarily talented.
I definitely agree, I don't like mixing TV shows and video game characters with religious items, it seems wrong to me.
But personally, these dream catchers seem fine to me without any problem, probably because I don't practice Native American culture, or I'm not Native American, or I'm just not into the practices, I don't know. I find it interesting, but I'm not too invested in it. I don't know how to explain it without seeming offensive.
But I know that I would not want to see Usagi on a cross! I'm Catholic and I like to respect God and Jesus,
Even religious scenes in the show like Hotaru on a cross seem wrong to me.