I’ve heard Ruptured Sky called inferior to moonbow more than once and I don’t see the reason. If anything it’s a better moonbow. It scores 12-15 damage against squishy ranged units and double the damage boost against dragons and beasts. If the opponent has 50 def, moonbow grants 15 extra damage, which Ruptured Sky would need 75 atk on the opponent to equal. It probably won’t get there, but it will only be behind by 1-2 points because opponents with 50 def rarely have less than 60 atk and often have more than 65. That’s a tiny price to pay for the benefits. The main reason why we don’t replace moonbow with Ruptured Sky is because it’s expensive.
Anyways, about Saias, I think it depends on the rest of the build? In the absence of other information, I tend to agree with the others. He has player phase potential (which isn’t conducive to being adjacent); he might want to stand apart from the group so that ranged units can’t fire at the unit behind him.