Dual Starhunt Summons are a different way of obtaining units added on Update 29. It consists of separate banners from the Hero Summon and, unlike the former, they do not refresh after an hour, but instead stay for a predetermined number of hours indicated on the banner. To summon on it, the currency used is Stardust. If you do a 10-summon 3 times, the fourth 10-summon is free, meaning you need 150 for a full rotation.
There are 3 types of summons you can get, 3-star, 4-star, and 5-star, and you can tell which one you get based on the appearance of the characters in the spirit bomb animation
There are several tells for what your summon will give you based on the prior animation:
If Goku's spirit bomb turns red, you're guaranteed a featured unit.
If Luffy falls flat on his face and gets back up, you will get 3 5 stars with a chance for a featured unit on all 3.
During a 5-star summon, Goku's hair will sometimes flash Super Saiyan, signifying that you are guaranteed 2 5-star units, one or both of which could be featured units.
The yellow circle indicator turns red when the unit is featured
A segment from Daft Punk's Robot Rock loops in the background when you get a featured unit