what are some ultimate items in this game?

[the_tick_rules]

If I remember correctly, combining the starmantle cloak with the Evasion class feature makes you immune to all weapon attacks contingent on beating a trivial Reflex save, which I have to imagine is a totally intended game mechanic and not the result of a lack of editing.

Not that good. It makes you immune to non-magical weapons. Against non-magical weapons or missiles you get a reflex save for half damage. It has no function against spells and since it specifically says weapons I would say it doesn't function against falling rocks, dragon breath etc. I'm also not entirely sure on the idea that it stacks with evasion. Evasion specifically says against an attack that deals half damage on a successful save. Weapon attacks don't have a normal reflex save for half.