If any of the following apply to you, don't use this build:

1 You suck
2 You are ******ed
3 You are a *****

or

4 You are amazing (then stack mejai's and leviathan)

important ones

5 You can't dodge a skill shot
6 You can't kite
7 You can't focus on a target
8 You can't farm
9 You don't buy wards
10 You don't buy potions

*I am really tired of seeing Morde's rushing hextechs. They are not enough to keep him alive, especially after the nerf. Morde needs to be tanky to be of any use in a game. I love to rush sunfire because it helps farm with your w, and gives a good amount of armor and health. I like to get a warmogs at the end because your health regeneration will be ridiculous.

Skills:
Max your e, then depending on your opponents either q or w. If you are outranged in a lane definitely upgrade your w, but if they are melee heavy go for your q. Of course, always upgrade your ult.

Runes:
These is meant to keep you a damage threat while still taking a lot of damage.

Masteries:
You are a tank.

Spells:
Ghost- for initiating and for running into a fight if you are late.

Ignite- this plus your ult equals kills for you.

I don't mind heal, flash, or exhaust. In my opinion, ghost and ignite help you get kills early on the best though.

Think of yourself as the juggernaut (*****). Your mindset= hey guys idgaf I am going in!

I like to solo top with Morde. I do not like mid with him because he is easy to harass and gank.

Farming:
You better be good at farming if you expect to be of any use later. Lucky for you, farming with Morde is sooooo easy.

Use your e to last hit. If you are smart you can bait your enemy into the cone and last hit while harassing.

Use your w on one of your own melee minions to lower the health of the others so you can last hit with your e.

I don't like to use q to farm early on because the health lost from all three abilities will add up and your opponent will have a health advantage without even harassing.

If you do it right you will push really hard. It's not a bad thing if you are dominating whoever is in your lane, especially when soloing top. More often than not you can 2v1 people because all of your abilities are aoe. When a jungler comes in for a gank, position yourself in a way where your e will hit both of them. When they go for you bring down the weaker one quickly. Usually the weaker one will run away then you can mess up the jungler. Do not try to 2v1 them if they have exhaust, obviously.

Against champions:
Like I said. You dgaf.

You can do a surprising amount of burst with your abilities and the shield makes enemies miscalculate your advantage. You can use this to your advantage when you are low on health by kiting until you abilities are off cool down. When you get your force of nature, you will regenerate a lot of your health while kiting which will annoy the enemy a lot.

You can get an easy kill in the beginning after sufficient harassing if you land an e, ult, and ignite. A lot of health will tick off and with ignite, even champions with healing or health regeneration will die.

In team fights offer to initiate. Go in by yourself spam your spells to keep your shield up long enough for your teammates to bring down the main damage threats on the other team or throw down some cc. If the other team is any good they will kill you, unfortunately, but your team will have plenty of time to avenge you fivefold. For this to work, you have to push their melee and tanks into their ranged. Then the other team will be in a nice clump for your team to aoe the **** out of them. The closer they are, the more champions you will hit with your spells and the more shield you will generate too.

Have some courtesy. It is very easy to ks with Morde but don't. You can farm whole waves of minions in seconds. Help out your team.