My Great Vault this week contains an Overwhelming Power Crystal, but the tooltip is slightly different from the one AMR is displaying (same Critical Strike rating, different Arcane damage):
Snapshot ID: 3b345a74ed864ca4860d1ff1ce68f9be
We did an update yesterday – it should match now. Note that this won’t impact the ranking/value of that trinket, as the self-damage is negligible.