DragonBattle API

Expected behavior

• Calling DragonBattle#initiateRespawn() or the other one with Collection arg, should start the dragon respawn sequence, advancing getRespawnPhase() as the vanilla animation runs
• Calling resetCrystals() should reset the crystals on the obsidian pillars

Observed/Actual behavior

• Calling initiateRespawn(List.of()) reports phase START for a moment, then immediately goes back to NONE on the next check. (it only tries to respawn torches for some reason)
• Calling initiateRespawn() (no-arg) never shows anything other than NONE.
• resetCrystals() does nothing at all
• No exceptions or warnings are printed to console in any case.

Steps/models to reproduce

1. Kill the dragon
2. Try calling any of these methods
3. Observe

Plugin and Datapack List

> plugins
[12:54:33 INFO]: ℹ Server Plugins (1):
[12:54:33 INFO]: Bukkit Plugins:
[12:54:33 INFO]:  - TestPlugin
> datapack list
[12:54:36 INFO]: There are 3 data pack(s) enabled: [vanilla (built-in)], [file/bukkit (world)], [paper (built-in)]
[12:54:36 INFO]: There are no more data packs available
> 

Paper version

> version
[12:55:38 INFO]: This server is running Paper version 26.2-112-main@c9e894d (2026-08-11T05:18:39Z) (Implementing API version 26.2.build.112-stable)
You are running the latest version
Previous version: 26.2-87-a95ae8d (MC: 26.2)

Other

My minimal test command

public class DragonBattleCommand {

    public static LiteralCommandNode<CommandSourceStack> command() {
        return Commands.literal("dragonbattle")
                .then(Commands.literal("start_print")
                        .executes(context -> {
                            Player player = getPlayer(context.getSource());
                            DragonBattle battle = getBattle(player);
                            Bukkit.getServer().getScheduler().runTaskTimer(TestPlugin.instance, () -> {
                                sendPhaseInfo(player, battle);
                            }, 0, 20);
                        return Command.SINGLE_SUCCESS;
                }))
                .then(Commands.literal("initiate")
                    .executes(context -> {
                        Player player = getPlayer(context.getSource());
                        DragonBattle battle = getBattle(player);

                        sendPhaseInfo(player, battle);
                        battle.initiateRespawn();
                        player.sendMessage("Initiated respawn");
                        sendPhaseInfo(player, battle);
                        return Command.SINGLE_SUCCESS;
                }))
                .then(Commands.literal("initiate_empty")
                    .executes(context -> {
                        Player player = getPlayer(context.getSource());
                        DragonBattle battle = getBattle(player);

                        sendPhaseInfo(player, battle);
                        battle.initiateRespawn(List.of());
                        sendPhaseInfo(player, battle);
                        return Command.SINGLE_SUCCESS;
                }))
                .then(Commands.literal("reset_crystals")
                    .executes(context -> {
                        Player player = getPlayer(context.getSource());
                        DragonBattle battle = getBattle(player);

                        sendPhaseInfo(player, battle);
                        battle.resetCrystals();
                        sendPhaseInfo(player, battle);
                        return Command.SINGLE_SUCCESS;
                }))
                .build();
    }

    private static void sendPhaseInfo(Player player, DragonBattle battle) {
         player.sendMessage("Respawn phase now: " + battle.getRespawnPhase().name());
    }

    private static Player getPlayer(CommandSourceStack source) {
        return (Player) source.getExecutor();
    }

    private static DragonBattle getBattle(Player player) {
        return player.getWorld().getEnderDragonBattle();
    }
}

Start by tracing the DragonBattle implementation behind initiateRespawn(), its Collection overload, resetCrystals(), and getRespawnPhase(). Use the supplied Java command and the listed Paper version to reproduce each behavior. Done means both respawn entry points advance through the vanilla sequence and resetCrystals() resets the obsidian-pillar crystals without warnings.