Tools Needed for New Mordekaiser Bottom Lane
The short end of the stick is you need a ranged sustain damage dealer in the middle lane and preferably a ranged support that pressures the lane to go with the Mordekaiser; good idea to start relic for Mordekaiser, most likely you will want a spell thief support.
Champions that would/could work middle lane: Azir Anivia Cassiopeia Karthus Kayle Lulu Orianna Zilean Kog'Maw (Ability Power) Corki (Attack Damage) Varus (Attack Damage) Twisted Fate Teemo (Ability Power) Ziggs
(NOTE: The hardcore utility mages of Lulu, Orianna, and Zilean despite being low damage can greatly buff up the Mordekaiser plus help his immobility get into range, Anivia also has very high utility and will lock down an area with all of her crowd control and zone controls but most importantly with Anivia is that she has sustain damage with her ultimate and long range basic attacks for sieges (600 units basic attacks) to make up for having a melee such as Mordekaiser instead of both an attack damage and ranged champion that a marksman provides.)
Champions that would/could work with as support:
Spell thief users: Annie Veigar Kennen Sona Nami Soraka Lulu Zilean Bard Brand Fiddlesticks Zyra Karma Vel'Koz Morgana
Coin users: Soraka Trundle Thresh Blitzcrank
Relic users: Alistar Braum Trundle Thresh Tahm Kench Blitzcrank Nautilus