According to MMO-Champion, the following is the Tier 10 balance relic:
The periodic damage from your Insect Swarm and Moonfire spells grants 44 critical strike rating for 15 sec. Stacks up to 5 times.
I hope I’m not the only one not impressed by this. This allows IS and MF to grant 220 critical strike rating, versus the current T9 idol which allows MF to grant 200 critical strike rating.
I realize adding insect swarm to the mix allows for some versatility, but this hardly seems worth an upgrade, especially if you have to spend badges for it.