देवेषु विश्वासटिप्पन्यः

East Asian mantrasAdhaka-s, today especially Japanese often preserve notable feature of the old religion that might have been forgotten to a degree in the homeland. E.g., the use of the chIna characters 双 (shuāng)=double 王 (wáng)=king for yama indicates his ancient twin nature which goes back to the RV.

In the Japanese context, this is said to signify yama and yamI who are respectively seen as the lord of the male and the female ghosts.

The RV presents another set of twin kings in this context, varuNa & yama:

ubhA rAjAnA svadhayA madantA yamam pashyAsi varuNaM cha devam ||