(1) Kostadinos IV
(2) Petros IV
(3) Aetos V
All these short routes lead to the north facing ridge. The ridge is a class 2 YDS and is basically a walk up to the summit. From the summit one can go down the east facing Perasma route which is a easy class 3 YDS or I UIAA. Aetos is the most dificult route on Ayios Ioannis but the rock is solid.