How does the timing work on damage redirection?
In a case like this you would chose the order that the damage happened one card at a time. If your goal was to destroy as many of the relics as possible you would do the damage something like this.


6 damage to the orb
6 damage to the relic you don't want destroyed this redirects to the orb destroying it
6 damage to the next relic
6 damage to the next relic


By remembering that each time you do damage it is considered separately, and if a response happens because of that damage then it takes place before the next damage from the original source is done. This is something that is important to remember and doing it all in the correct order can be the difference between winning and losing a game. 

The only thing that needs to be done in the order they came out is the start/end of turn effects on a card. Such as the what happens during the villain/environment turn.