you can play with this build on jug and top, the rest of the line hasn't been tested so if someone wants to write about it I'll gladly read it and improve the post, for now I have a winrate of under 70%.in general I recommend going for AP and not for tank but it depends on your team, I take AP 90% it is a win when it comes to tank it is a bit different but it also depends on your style of play.
Oden's advice on this character is to use it when you have max shield, if not, use it when you can die and the shield usually works on it, e.g. ignait etc.

try to take the best characters from the opposing team for better stats with r always take the best person but if you believe that he will not defeat him in 1 vs 1 you can take other characters I do not recommend tanks they have too much life and it is hard to kill them in such a short time
as for the gameplay mordekaiserme it is very simple just don't misplace q always have the passive activated at the beginning you can almost kill everyone as for level 1 the passive gives a lot which translates into a better start but only fight if you have runes for AP and not tank because then the passive gives very little
try to help and take the ones who cause the most trouble or have yummi on them if you take someone who has yummi on them all the time it is a much easier enemy to kill watch out because they will often want to gank in 3 or more if you have a big advantage on the opposing top