Discovered this by accident, but a Sinomacrops will scream at and scare away all the mantas that surround the Basi. Not required, but the easiest way I found was to set my Sino to have "auto scream" enabled and "scream requires aggro" disabled. When you get semi close it'll scream which will make all, or most of the Mantas flee for long enough to feed the Basi. Hope this helps and happy whaling!!

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