Can you use Rek'Sai's ability and ready it again on the same conquer with Hall of Legends?

Ruling: Yes, you can use Rek'Sai's ability and ready it again on the same conquer with Hall of Legends by stacking the triggers to your advantage.

Sequence:

• Both Hall of Legends and Rek'Sai have "on conquer" triggers, so you order them however you like
• Order the chain Hall > Rek'Sai
• Rek'Sai resolves and exhausts itself
• Hall resolves and readies it

Nuances:

• If Rek'Sai was already exhausted before the conquer, you could order them in reverse (Rek'Sai > Hall) to ready her first with Hall, then use her ability immediately