Deathmist Raptor increases the green mana symbol count for G/W Devotion and provides more inevitability for the deck
Ive gone on record to say that people need to play more three mana 2/4s, so its safe to say that a three mana 5/4 is another statline Id be overjoyed to have as a blocker
Other effects that set its power to specific values that start to apply after the ability resolves, including future instances of the ability, will overwrite that effect
When this dies make a 1/1 White Soldier for each quest counter here
Besides being slightly lighter, there is one distinct difference I can see and it comes down to the print line that drops down from the black mana symbols in the cards mana cost
A recurring theme of Rise of the Floodborn has been improving the card draw ability of inks that didnt get much of it in the first set, like Emerald and, in this case, Sapphire