Could try for some expert mode treasure bags, in Hope's of an arkalis(sp?) Or just keep making large worlds and look for the opening below a certain depth. If you have the drill containment unit... well, I guess you wouldn't need the enchanted sword in either case.
It's a pain to find them, ngl. It doesn't seem as guarenteed as the wiki makes them out to be for every single world (I play around with about a dozen worlds on mobile, only two of those seem to have an enchanted shrine that isn't completely obscured or non-existent.)
Sorry if that wasn't much help, but expert mode treasure bags for dev weapons is an option, if arkalis is what you're looking for.
Edit: forgot to mention the obvious, but in case you've never visited the wiki... you do need to look for a shaft leading a ways down from, what is supposed to be, relatively close to the surface level... but again, I've reached drill containment unit on Mobile, and I've only noticed like 2 out of 10+ worlds that actually have the shrine, for me.
One of those worlds MIGHT HAVE had a second shrine, but... again, unless someone confirms a better way to locate them from the surface, nothing short of terraforming a world is going to find a hidden one in my experience. Just imo tho.