Was thinking on this, but it feels like for something like the 5 star ones, it would be better if they could come from running a set number of castrum / Dalraida runs rather than be given out via RNG. Duels being excluded from the equation, it never feels good having to run something hundreds of times without having at least some kind of pity system in place that can let you get one after X number of runs.

Like would it be better to have a chance to get something in 50 runs of castrum, or just give the person something after 50 runs of castrum? If 50 is too easy because they want them to come from duels, they could make it 75 runs to assure you get the item.