Select the entity (monster) or character and in the entity inspector (select the entity tab) you will see 8 boxes of numbers arranged in a square selecting one of those (angles) will rotate your monster or character selected when it is highlighted by using shift and left click to select your entity and then select a number value from the square .....you'll see two buttons up and dn next to them ( those are for doors).
those values will rotate your monster or character.
or you can type in a value for the angle anywhere from 0 to 359
deselect by hitting escape.
let us know how it goes