Mude para este :

local reward = {
    item = 2152, --ITEM ID!
    count = 1 -- How many?
}
 
function onKill(cid, target, lastHit)
    if isPlayer(cid) and isPlayer(target) and lastHit then
      doPlayerAddItem(cid, reward.item, reward.count)
    if getPlayerIp(cid) == getPlayerIp(killer) then
        doPlayerSendTextMessage(cid, MESSAGE_INFO_DESCR, "Você não ganha nada matando MC")
        return False
        end
return true
end

esse codigo que vc adionou eu ja havia tentado hoje e ao mesmo n funciona nesse script.

Tente o seguinte então :

local reward = {
    item = 2152, --ITEM ID!
    count = 1 -- How many?
}
 
function onKill(cid, target, lastHit)
    if isPlayer(cid) and isPlayer(target) and lastHit then
     if ((isPlayer(cid) and isPlayer(target)) and (getPlayerIp(cid) ~= getPlayerIp(target))) then
      doPlayerAddItem(cid, reward.item, reward.count)
        end
return true
end

tbm deu o msm erro.

Tente fazer isso :

"data/creaturescripts/scripts/kill.lua"

function onKill(cid, target, lasthit)
    if ((isPlayer(cid) and isPlayer(target)) and (getPlayerIp(cid) ~= getPlayerIp(target))) then
	    doPlayerAddItem(cid, 2152, 1)
    end
    return true
end

"data/creaturescripts/creaturescripts.xml"

<event type="kill" name="killplayer" event="script" value="kill.lua"/>

"data/creaturescripts/scripts/login.lua"

registerCreatureEvent(cid, "killplayer")