What is the best way to do this?
I`m not sure there is a 'best' way. You can make the objects transparent and turn them solid one by one. You can make them a background color and change that color one by one. You could move a plane across the world to reveal the objects one by one...
Whatever you choose it sounds like you need a WakeupOnElapsedFrames(someFrameInterval) wakeupCondition for your custom reveal Behavior.
regards