Once upon a time, a box was given unto man. We were told not to open it, but curiosity got the best of us, and we opened it.
Every disease flooded from the box, but at least at the bottom there was "hope".
Once again, you have done the same. But with a different box.
The name of this box is Kanji Kentei, and you may read about it on wikipedia. Now, to answer your question, this is what mastering the Kanji is:
Level 1
Tests the ability to read and write all 6355 kanji in levels 1 and 2 of JIS X 0208, with their on readings and kun readings
Requires the ability to use the kanji in sentences and to choose the most appropriate kanji for a given context
Tests special or unusual kanji readings
Tests ateji
Tests knowledge of synonyms and antonyms
Tests ability to differentiate between homonyms
Tests special compound words
Tests complex radicals
Tests kanji unique to the Japanese language
Tests classical Japanese proverbs and idiomatic expressions
Tests place and country names
Tests the ability to recognize the relationship between modern and ancient or old character forms