Devas are CR10 celestials who among other things, can change shape into any humanoid or beast below their CR (which is pretty much every beast in the game). I'm going to ignore humanoids for now because it gets a bit messy trying to figure out which of their actions / abilities / traits are innate to that creature vs any class levels they may have. Anyway, what's interesting is the way this change shape feature is worded:
"In a new form, the deva retains its game statistics and ability to speak, but its AC, movement modes, Strength, Dexterity, and special senses are replaced by those of the new form, and it gains any statistics and capabilities (except class features, legendary actions, and lair actions) that the new form has but that it lacks."
This means the Deva can effectively take on features from beast statblocks below CR 10, in addition to the 136hp, resistances, multiattack, and extra 4d8 radiant damage on attacks it already possesses. Which can be... strong.
An example I came up with is a Deva transforming into the Spotted Lion from the Bigby's giants book. In this form, the downsides are the Deva would lose it's flight and go down to 60ft move speed, and it's AC is reduced from 17 to 15. But in return, the Deva gains 23 strength (up from 18), pack tactics, and I think it would also get the lion's rend attack, which hits for a hefty 2d8 +6 at 10ft range, as well as adding that radiant I mentioned, and can also knock targets prone on a charge, getting a BA attack for free if it succeeds. While the loss of flight is unfortunate, these offensive options push the Deva into the CR 13+ range (based off a rough online calculator I use), purely via tactics, without changing the statblock as written*.
*I guess the stats do change given it adds abilities to the creature, but the stats are added by using an ability the Deva already possessed, so it's basically vanilla
Devas are CR10 celestials who among other things, can change shape into any humanoid or beast below their CR (which is pretty much every beast in the game). I'm going to ignore humanoids for now because it gets a bit messy trying to figure out which of their actions / abilities / traits are innate to that creature vs any class levels they may have. Anyway, what's interesting is the way this change shape feature is worded:
"In a new form, the deva retains its game statistics and ability to speak, but its AC, movement modes, Strength, Dexterity, and special senses are replaced by those of the new form, and it gains any statistics and capabilities (except class features, legendary actions, and lair actions) that the new form has but that it lacks."
This means the Deva can effectively take on features from beast statblocks below CR 10, in addition to the 136hp, resistances, multiattack, and extra 4d8 radiant damage on attacks it already possesses. Which can be... strong.
An example I came up with is a Deva transforming into the Spotted Lion from the Bigby's giants book. In this form, the downsides are the Deva would lose it's flight and go down to 60ft move speed, and it's AC is reduced from 17 to 15. But in return, the Deva gains 23 strength (up from 18), pack tactics, and I think it would also get the lion's rend attack, which hits for a hefty 2d8 +6 at 10ft range, as well as adding that radiant I mentioned, and can also knock targets prone on a charge, getting a BA attack for free if it succeeds. While the loss of flight is unfortunate, these offensive options push the Deva into the CR 13+ range (based off a rough online calculator I use), purely via tactics, without changing the statblock as written*.
*I guess the stats do change given it adds abilities to the creature, but the stats are added by using an ability the Deva already possessed, so it's basically vanilla