What is Mordekaiser's most reliable build when he mainly has to win through contact duration?

The most reliable build remains the one that first buys useful contact time before chasing the AP ceiling. Mordekaiser mostly wins when he imposes his rhythm long enough for passive, realm, and chase to stop being theoretical.

Rylai or Liandry on Mordekaiser depending on whether he mainly has to stick or wear down?

Rylai comes first when the real problem is keeping the target in contact long enough. Liandry becomes better when Mordekaiser already holds useful distance well and mainly needs duel duration to punish thicker profiles harder.

When should Mordekaiser buy Stasis without betraying his duel logic?

Stasis is justified when the enemy can break the realm or the entry through burst that is too brutal before duration has time to work. The enchant is not there to flee the champion's identity, but to buy the seconds that finally make that identity playable.

Mordekaiser Wild Rift Best Build Guide (Patch 7.2a)

Mordekaiser wins less through instant burst and more through progressive oppression: he locks a target, forces contact, activates his passive and drags the exchange into a duration he is more likely to win than many other champions. His reference build therefore has to support duration, not only…