Despite the many items listed before, there were still countless other precious treasures spread around the world.
Nouvan couldn't possibly list so many items that one could use to extend their life spans with his limited knowledge.
Of course, different items also gave different life spans amounts.
The unicorn's blood could only extend one's life by a year. And it had to be a wild unicorn not belonging to any human, still pure and untouchable.
Dragon's scale...5 years. It had to be the scale from the dragon of life with more than 1000 years life spans.
Fruit of life, 3 years. One could only find this at the Dwarf kingdom. It was their treasured fruits that even the elves didn't have.
Mermaid tear, 2 years.
One could only find the mermaid at the underwater kingdom where legendary oceanic creatures such as kraken and mermaids live.