>>715130118
If you already wasted a lot of your pulls early during launch, then by chance you might already have tons of SR dupes, which are better than just two copies of Kitasan. so you're better off borrowing her.
But if you're like me, who already got SC and FM from rerolling and still has a lot of saved carats, then dumping everything on the Kitasan banner is the better option because I can build up a lot of early SR dupes.
Even if I get unlucky and only pull a single copy, I can use future event rewards to uncap her three times, making the guest card slot viable for a wide range of builds.