What are the rewards for the 7th and 8th Relay Defense maps?

3 Dueling Crests each, so feel free to stop trying if you're having problems.

3 Dueling Crest each, I believe.

Not worth it, I believe.

They’re both right, it’s 3 dueling crest for each abyssal map which totals to 6. It’s up to you if you want them.