on break:
if player's world is "ul_RPGWorld":
if event-block is stone:
give player event-block
set event-block to cobblestone
wait 60 ticks
set event-block to stone
on break:
if player's world is "ul_RPGWorld":
if event-block is cobblestone:
give player event-block
set event-block to bedrock
wait 60 ticks
set event-block to stone
this should work not tested