Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
your highest dmg is your Q but if u have ranged champ on lane like teemo try to harass him with E don't spam your abilites until u have hextech gun and remember that your R will be best way to heal yourself your W is basically for heal or extra speed towards allies use your w and then reactivate it again near minions or champions
Remember that Morde don't have any cc only slow from rylai or frozen mallet so dont fight alone vs more than 2 champions cause they will stun you or snare and you cant do nothing