Like does it have boosted shiny odds, boosted item drops (herba mystica, shards, exp candies, etc) or what?
The event is out and now the information is in. The Shiny rate for this event is standard. Rewards for winning this Raid are: - Slither Wing / Iron Moth - Exp. Candy L (24.21%) - Exp. Candy XL (11.58%?) - Rare Candy (4.21%) - Swift Feather / Muscle Feather (10.53%) - Kelpsy Berry (8.42%) - Big Pearl (12.63%) - Pearl String (2.11%) - Nugget (5.26%) - Timid Mint (2.11%) - PP Up (3.16%) - Bottle Cap (2.11%) - Current Type Tera Shard (11.58%) - Ability Capsule (2.11%)
Source
Another source
It has a met level of 75, rather than the usual 52 to 60 you'd get from hunting those Pokemon in the crater, and like all 5-star raids it comes with four max IVs.