For your sacred seal, ideally, you'd use one that weighs zero such as the Erdtree Seal, in order to Elden Ring Runes get the most from the Blue Dancer Charm here because that is going to lower your equip weight, and as your equip weight goes down you gain more and more attack power from that Talisman. If you don't have enough Faith here for the Erdtree Seal, the ideal one would be like the Frenzied Flame Seal or any seal that weighs zero.
What you want to use for armor is something extremely lightweight because the Blue Dancer Charm has sort of soft cap break points at 8,16, 24, and then once you hit 30 you get no effect. That doesn't mean the damage difference from 8 to 8.1 is different you don't go from like 80 to 40 damage if you hit 8.1, it's sort of like a sliding scale, the more you get closer to 30 the less damage you deal. So it doesn't have to be exactly on the nose on these things but our advice is don't go much heavier than 16. If you go too much past 16, we don't feel like there's many benefits in using the Blue Dancer Charm, so you should either aim for about 16 weight or aim for about 8 weight in order to get 8 weight you basically can use the black bow, a Talisman that or a sacred seal that weighs nothing, and then your Talisman.
So you'd wear no armor and you'd hit right around that 8 points, or you could throw on some one piece of armor that weighs like one or something to get some armor if you just want to wear something so you're covered, but you want to be close to that 8 breakpoint. Just keep in mind that it's sort of a sliding scale from zero all the way up to 30 and the closer you are to cheap Elden Ring Runes zero the more damage you're going to deal.