'bestist' 
Betterer then...
That is best
est.
[fact]
'Dwarf' is of Germanic/Nordic origin, so the original plural would have been 'Dwarfen'
Usually when such words are adopted in English, the 'n' becomes 's'.
Notable exceptions are words like 'horse' which would have been expected to follow the rule of 'ox' to 'oxen' i.e. 'horse' to 'horsen' not 'horses'
[/fact]