<?xml version="1.0" encoding="UTF-8"?>  
<mod name="Summon Boost System" version="2.0" author="LuckOake" contact="none" enabled="yes">
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<config name="boost"><![CDATA[
bstor = 17824 -- Storage do boost
percent = 20 -- Quantos por cento a vida do summon aumentará ao receber o Boost
maxboost = 50 -- Level máximo de boosting
 
function isSummon(cid)
    return isMonster(cid) and isPlayer(getCreatureMaster(cid))
end
 
function getBoostingLevel(cid)
    return getCreatureStorage(cid, bstor) == -1 and 0 or getCreatureStorage(cid, bstor)
end
 
function doCreatureBoost(cid, levels)
    for i = 1, levels do
        setCreatureMaxHealth(cid, getCreatureMaxHealth(cid)*(percent/100+1))
    end
    doCreatureAddHealth(cid, getCreatureMaxHealth(cid))
    return doCreatureSetStorage(cid, bstor, getBoostingLevel(cid)+levels)
end
]]></config>
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<action actionid="6310" allowfaruse="1" event="script"><![CDATA[
    domodlib('boost')
    local pos = getCreaturePos(itemEx.uid)
    
    if not isSummon(itemEx.uid) then
        doPlayerSendCancel(cid, "You can only boost a summon.") return true
    elseif getCreatureMaster(itemEx.uid) ~= cid then
        doPlayerSendCancel(cid, "You can only boost your own summon.") return true
    elseif getBoostingLevel(itemEx.uid) >= maxboost then
        doPlayerSendCancel(cid, "Your summon is already at the max boosting level ("..maxboost..").") return true
    end
    
    doCreatureBoost(itemEx.uid, 1)
    doPlayerSendTextMessage(cid, MESSAGE_STATUS_CONSOLE_BLUE, "You've boosted your "..getCreatureName(itemEx.uid)..". It's boosting level is now "..getBoostingLevel(itemEx.uid)..".")
    doSendAnimatedText(pos, "BOOST +"..tostring(getBoostingLevel(itemEx.uid)), TEXTCOLOR_YELLOW)
    registerCreatureEvent(itemEx.uid, "AttackBoost")
    doSendDistanceShoot(getCreaturePos(cid), pos, 3)
    doSendMagicEffect(getCreaturePos(itemEx.uid), 36)
    doRemoveItem(item.uid, 1)
return true
]]></action>
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<event type="attack" name="AttackBoost" event="script"><![CDATA[  
function onAttack(cid, target)
        registerCreatureEvent(target, "StatsBoost")
return true
end
]]></event>
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<event type="statschange" name="StatsBoost" event="script"><![CDATA[  
local overflow_protection = {}
 
function onStatsChange(cid, attacker, type, combat, value)
    domodlib('boost')
    if type == STATSCHANGE_HEALTHLOSS and value >= 1 then
        if overflow_protection[attacker] then
            overflow_protection[attacker] = nil
            return true
        end
        
        local dmg = math.floor(value*(getBoostingLevel(attacker)/10+1))
        overflow_protection[attacker] = true
        doPlayerSendTextMessage(getCreatureMaster(attacker), MESSAGE_STATUS_DEFAULT, "Your "..getCreatureName(attacker).." deals "..dmg-value.." boost damage to "..(getMonsterInfo(getCreatureName(cid)).description)..".")
        doTargetCombatHealth(attacker, cid, combat, -dmg, -dmg, CONST_ME_NONE)
        return false
    end
return true
end
]]></event>
</mod>

Você só precisa configurar aqui:

bstor = 17824 -- Storage do boost
percent = 20 -- Quantos por cento a vida do summon aumentará ao receber o Boost
maxboost = 50 -- Level máximo de boosting

E aqui:

<action itemid="6310" allowfaruse="1" event="script"><!--[CDATA[

No lugar de 6310, você coloca o ID do seu item de Boost.

E se souber o que está fazendo, pode também editar a fórmula do dano extra do boost:

local dmg = math.floor(value*(getBoostingLevel(attacker)/10+1))

Boosting:

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Exemplo de ataque de um minotaur com boosting level 15: