Early game Mordekaiser is grabbing your first skill and supporting the jungle if starting bottom and then following your bot, you will always be supporting your bot player and pulling in minions to control the lane. Once you get your next ability you can begin the slamming, still be careful as you have low HP. Focus when the enemy is a bit forward and not close to their ally, this will allow you to grab their focus and get off a ton of damage. You should be using yourself as a shield for your ally, use health pots when less then half health.

In Mid game you will be mainly be continuing what you did in early game phase by moving with your bot, poking enemies and attacking when requested too. Though at this point if the enemy team loses its tower to you due to your demolish, the bot might start roaming if so you will roam with them. Follow the bot and only deviate when other teammates request assistance, you still cant tank a ton of damage but surprising the enemy can get off a lot of DPS.

a

In Drake fights from early to mid game you will participate in them if asked for assistance but if you have your bot and mid working on it, you will act as the body guard since your DPS isnt that high at this stage. At this point youll mainly focus on stopping the enemy team from getting close and absorbing any drake killing hits, if you see the jungler you will want to use your R to stop them from using smite. In later midgames to end game, you will assist in DPS if the enemy team isnt coming or your able to assist DPS until the enemy team shows up.

a

Your Ultimate, oh boy.. You'll almost rarely be using your ultimate as it will be entirely situational as you have to worry about the lives of your team and your bot. Using your ultimate in a bad situation can get your bot player killed, sure you stopped one of the enemies but that other one can possibly kill your bot player. You should only be using the Ultimate to stop enemies in their tracks, hold them in place near tower or using it on enemies when they are alone not you.