Mordekaiser vs Akali Top Matchup
Mordekaiser Top wins 49.5% of 1,350 Low Elo games against Akali Top, -2.0 points vs expected, 2-patch window 26.19-26.20.
Researched on LoL patch 26.20. Tips are written to hold at any rank; stats come from Low Elo ranked games up to patch 26.20.
Why Akali is favored
Akali can punish the gap between Mordekaiser's Obliterate(Q) casts: her Five Point Strike(Q) is available much more often, and her mobility helps her dodge his Q or Death's Grasp(E). Mordekaiser mains note that when he misses Q, Akali can land several Q trades before his three-hit Darkness Rise(P) activates.
How to play as Mordekaiser
Use Realm of Death(R) after Akali spends Twilight Shroud(W); her shroud will not come with her into the Realm.
Twilight Shroud(W) stays on the original map when Akali enters or leaves Mordekaiser's Realm of Death(R); it does not travel between the two areas.
Akali's Five Point Strike(Q) has a much shorter cooldown than Mordekaiser's rank-one Obliterate(Q), while Mordekaiser needs three attacks or spells to activate Darkness Rise(P); a missed Q gives Akali room for repeated poke before his aura starts.
How to play as Akali
Save Twilight Shroud(W) for the Realm if Mordekaiser still has R; a shroud cast outside stays behind, while Shuriken Flip(E) can help you avoid his pull.
Sources
These notes come from r/akalimains and r/MordekaiserMains, checked against the champions' abilities.