par·a·gon

– noun
1. a model or pattern of excellence or of a particular excellence.
–verb
2. to compare; parallel.
3. to be a match for; rival.
4. to surpass.

nem·e·sis

– noun
1. something that a person cannot conquer, achieve, etc.
2. an opponent or rival whom a person cannot best or overcome.
3. the goddess of divine retribution.
4. an agent or act of retribution or punishment.