What happens if you multiply a point with its order on complete Edwards curves?
Actually multiplying an elliptic curve point $G$ by its order $q$ gets you to the neutral element of the group, i.e., the point $O$ such that $P+O=P$ for any point P.

In a generic elliptic curves this point is the point at infinity $O$. However on Edwards curves, this point is $(0,1)$, i.e., it can be represented by affine coordinates. This is also stated on wikipedia. 

Therefore, multiplying a point by its order, on an Edwards curve, gets you the point $(0,1)$

This means that on Edwards curves: $P+(0,1)=P$ for any point $P$.