How to Unlock Grand Library - Elden Ring
First, you have to go to the Debate Parlor Grace in the academy.
Follow the path to Rennala.
And summon two cooperators.
After that, enter the mist for the 1st cutscene.
Attack 3 ground girls with Golden glow.
And then attack Rennala when she falls down.
You will need to kill three more girls with golden glow.
Attack Rennala until she has no health.
The 2nd cutscene starts.
You have to dodge magic attacks.
Try to stay behind Rennala.
And then attack Rennala at least once.
After that, wait for two loot prizes.
Remembrance of the full moon queen.
Great rune of the unborn.
Next, you will need to listen to Rennala.
Activate Raya Lucaria grand library grace.
Get option to redistribute skill points.
Examine the great rune of the unborn.
And then go to Roundtable hold.
You have to talk to Enia to get a free talisman pouch.
Talk to Enia again.
Select receive power from remembrance.
Pick scepter or moon ( I chose moon).
Buy Rennala's outfit.