Hello,

The Mist Dragon says : " Before you engage the Dragon in psychic combat , roll 2 dice. You must use the lowest result for your attack roll and the Dragon uses the highest result for its attack roll ."

Can I use fate to reroll one of the 2 dice before attack rolls are assigned ?

After the attack rolls are assigned, can I use fate to reroll my attack roll ? If yes, what happens if the reroll is higher than the Dragon's roll ?

Thanks in advance !

You may use fate to reroll one of the two, after that neither you nor anyone else may use fate to do another reroll as is the case anytime that a character rolls multiple dice.

You may use fate to reroll one of the two, after that neither you nor anyone else may use fate to do another reroll as is the case anytime that a character rolls multiple dice.

This is correct

You cannot reroll a die after its result has been used for an effect. Once you determine which result is the lowest and which is the highest, you are using the current results and they cannot be rerolled afterwards.

So, paying fate for the Mist Dragon looks like a waste; you can reduce the gap if you reroll the lowest die and get a higher result, but there's no way for your character to get a higher roll than the Mist Dragon.