Try to regain all chaos items from your inventory (this means to remove them) and go past ward. Take apart the KeyinaCloak to get the snuffus cloak and the pandora's keys.
Put on the cloak, and try to grab it from the bottom to make a glider-type thingamajiggy.
Put the bookmark of eternity as far out in the middle of the chasm as you can, and hold on to the rope and try to swing, letting go at the apex of the swing and gliding to the other end, like Knuckles almost. ^_^

I think I got it.