linger.lua

local bodyswap = reqscript('bodyswap')

if df.global.gamemode ~= df.game_mode.ADVENTURE then
    qerror("This script can only be used in adventure mode!")
end

local adventurer = df.nemesis_record.find(df.global.adventure.player_id).unit
if not adventurer.flags2.killed then
    qerror("Your adventurer hasn't died yet!")
end

function getHistoricalSlayer(unit)
    local histFig = unit.hist_figure_id ~= -1 and df.historical_figure.find(unit.hist_figure_id)
    if not histFig then
        return
    end

    local deathEvents = df.global.world.history.events_death
    for i = #deathEvents - 1, 0, -1 do
        local event = deathEvents[i] --as:df.history_event_hist_figure_diedst
        if event.victim_hf == unit.hist_figure_id then
            return df.historical_figure.find(event.slayer_hf)
        end
    end
end

local slayerHistFig = getHistoricalSlayer(adventurer)
local slayer = slayerHistFig and df.unit.find(slayerHistFig.unit_id)
if not slayer then
    slayer = df.unit.find(adventurer.relationship_ids.LastAttacker)
end
if not slayer then
    qerror("Killer not found!")
elseif slayer.flags2.killed then
    local slayerName = ""
    if slayer.name.has_name then
        slayerName = ", " .. dfhack.TranslateName(slayer.name) .. ","
    end
    qerror("Your slayer" .. slayerName .. " is dead!")
end

bodyswap.swapAdvUnit(slayer)