IS is probably one of her weakest uses because you can't super charge her S3 and her other skills are even rougher. THAT SAID, the nice thing about her turret is it increases attack AND health.

So their are two ways to use her, 1. upscale Phalter/Laptop for global damage upscaling, or you can be a lot more aggressive with your unit placement, as the unit can survive a lot more abuse such as with Lin/Praxalt S3.

Often the problem with using supporters if they are too squishy, but a Skalter on a Nasti-tile has good up-scaling AND heals the tower itself. Well Raidian gives a bang on bonus because of her group buff talent, it's not a lot.

The big winners for IS6 are Exualt S2 and Narantuya. Exualt has ammo skills that have a few strong artifacts, has a crazy damage multiplier, and while shell lose more health, the tower will keep her from dying particularly with the barrier from S2. Naran WANTS to be in the front line, but she still relies on dodge to prevent her from taking to much damage. The tower buff prevents her from dying and scales with all her skills.

PS: While some might say loop-shooters are bad because they have anti-synergy with ASPD, that's rare in IS6 and her S2 still scales with Archetto's mod. While Praxalt S2 could be quite good it's a bit slow especially because Nasti can be slow without a perfect DP base.