I think that Asoka was enlightened, because although he used to be a ruthless conqueror, after seeing the destruction he had caused, he had converted into buddhism which from there on was a good and peaceful ruler according to the legend.
An example would be how he believes that one who does wrong should be forgiving as far as it is possible to forgive him. This means, according to my own understanding of this, that if someone does something wrong, they should be spared and forgived.
Second example is that after Asoka’s death, his symbol was adopted on the Indian flag. This was probably a sign that the people liked his rulership and decided to use his symbol on the flag because why else would they even consider putting his symbol on the flag if he was ruthless ruler?
My last reason is that he introduced a form of government based in Buddhist spiritual belief.