1) Go to Route 12
2) Talk to the Swellow that is beside the girl on the right that challenges you.
3) Follow the Swellow into the tree den and play the mini-game.
*Tip: Don't let any of the Pokemon see you move in any direction.
4) After getting the hint, go to Oldpine City and go up to the caves.
5) On the upper left of the cave close to the statue, you will find a den filled with spiders.
6) Go through that cave using the candle.
*Tip: Having Haunter haunt you during this helps with the mini-game big time!
7) Go to Dorocoast Town and talk to the replacement Gym Leader
8) Complete the Wedding Arc (as I call it) and then go to the Eastbourne City Gym Leader's home
9) Press "x" on the fridge and turn on the switch
10) The Pokeball in the corner of the room contains the 3rd Relic
11) I will not take credit for this work! Fourth Relic directions here: viewtopic.php?f=19&t=2531&p=23984&hilit=Blackfell#p23984
Thank you so much MrIbby because I spent hours just looking for the correct path and your forum gave it to me! Thank you!
5th Relic yet to be found.