what triggers first: Zaun Warrens effect, or Kai'Sa Survivor's effect?

When you conquer a battlefield with Kai'Sa, Survivor at Zaun Warrens, both abilities trigger simultaneously because they share the same trigger condition ("When you conquer").

According to RiftJudge FAQ #5981 and RiftJudge FAQ #6614, because these triggers are simultaneous, you as the controller choose the order in which they are placed on the chain.

Sequence:

1. Conquer Event: You conquer the battlefield.
2. Trigger Placement: Both the Kai'Sa, Survivor ("When I conquer, draw 1") and Zaun Warrens ("When you conquer here, discard 1, then draw 1") triggers are placed on the chain. You choose the order.
3. Resolution: The chain resolves in LIFO (Last-In, First-Out) order.
   • If you place Kai'Sa's trigger on the chain last, it will resolve first.
   • If you place Zaun Warrens' trigger on the chain last, it will resolve first.

Example: If you want to draw from Kai'Sa before discarding for Zaun Warrens, you would place the Zaun Warrens trigger on the chain first, and the Kai'Sa trigger on top of it. When the chain resolves, you draw from Kai'Sa, then discard and draw from Zaun Warrens.