Lemuria,
(This card is always treated as "Umi".)
All WATER monsters gain 200 ATK/DEF. Once per turn, during your Main Phase: You can have all WATER monsters you currently control gain Levels equal to the number of WATER monsters you currently control, until the end of this turn.
local s, id, o = GetID()
function s.initial_effect(c)
	--Activate
	local e1 = Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--Atk/def
	local e2 = Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetCode(EFFECT_UPDATE_ATTACK)
	e2:SetRange(LOCATION_FZONE)
	e2:SetTarget(aux.TargetBoolFunction(Card.IsAttribute, ATTRIBUTE_WATER))
	e2:SetTargetRange(LOCATION_MZONE, LOCATION_MZONE)
	e2:SetValue(200)
	c:RegisterEffect(e2)
	local e3 = e2:Clone()
	e3:SetCode(EFFECT_UPDATE_DEFENSE)
	c:RegisterEffect(e3)
	--lv
	local e4 = Effect.CreateEffect(c)
	e4:SetDescription(aux.Stringid(id, 0))
	e4:SetType(EFFECT_TYPE_IGNITION)
	e4:SetRange(LOCATION_FZONE)
	e4:SetCountLimit(1)
	e4:SetTarget(s.lvtg)
	e4:SetOperation(s.lvop)
	c:RegisterEffect(e4)
end
function s.cfilter(c)
	return c:IsFaceup() and c:IsAttribute(ATTRIBUTE_WATER) and c:GetLevel() > 0
end
function s.lvtg(e, tp, eg, ep, ev, re, r, rp, chk)
	if chk == 0 then
		return Duel.IsExistingMatchingCard(s.cfilter, tp, LOCATION_MZONE, 0, 1, nil)
	end
end
function s.lvfilter(c)
	return c:IsFaceup() and c:IsAttribute(ATTRIBUTE_WATER)
end
function s.lvop(e, tp, eg, ep, ev, re, r, rp)
	local c = e:GetHandler()
	if c:IsRelateToEffect(e) then
		local lv = Duel.GetMatchingGroupCount(s.lvfilter, tp, LOCATION_MZONE, 0, nil)
		local g = Duel.GetFieldGroup(tp, LOCATION_MZONE, 0)
		local mg, fid = g:GetMaxGroup(Card.GetFieldID)
		local e1 = Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_FIELD)
		e1:SetCode(EFFECT_UPDATE_LEVEL)
		e1:SetRange(LOCATION_FZONE)
		e1:SetTargetRange(LOCATION_MZONE, 0)
		e1:SetTarget(s.efftg)
		e1:SetValue(lv)
		e1:SetLabel(fid)
		e1:SetReset(RESET_EVENT + RESETS_STANDARD + RESET_DISABLE + RESET_PHASE + PHASE_END)
		c:RegisterEffect(e1)
	end
end
function s.efftg(e, c)
	return c:GetFieldID() <= e:GetLabel() and c:IsAttribute(ATTRIBUTE_WATER) and c:GetLevel() > 0
end


Lemuria,
(This card is always treated as "Umi".)
All WATER monsters gain 200 ATK/DEF. Once per turn, during your Main Phase: You can have all WATER monsters you currently control gain Levels equal to the number of WATER monsters you currently control, until the end of this turn.
-- Lemuria,
local s, id, o = GetID()
function s.initial_effect(c)
	--Activate
	local e1 = Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--Atk/def
	local e2 = Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetCode(EFFECT_UPDATE_ATTACK)
	e2:SetRange(LOCATION_FZONE)
	e2:SetTarget(aux.TargetBoolFunction(Card.IsAttribute, ATTRIBUTE_WATER))
	e2:SetTargetRange(LOCATION_MZONE, LOCATION_MZONE)
	e2:SetValue(200)
	c:RegisterEffect(e2)
	local e3 = e2:Clone()
	e3:SetCode(EFFECT_UPDATE_DEFENSE)
	c:RegisterEffect(e3)
	--lv
	local e4 = Effect.CreateEffect(c)
	e4:SetDescription(aux.Stringid(id, 0))
	e4:SetType(EFFECT_TYPE_IGNITION)
	e4:SetRange(LOCATION_FZONE)
	e4:SetCountLimit(1)
	e4:SetTarget(s.lvtg)
	e4:SetOperation(s.lvop)
	c:RegisterEffect(e4)
end
function s.cfilter(c)
	return c:IsFaceup() and c:IsAttribute(ATTRIBUTE_WATER) and c:GetLevel() > 0
end
function s.lvtg(e, tp, eg, ep, ev, re, r, rp, chk)
	if chk == 0 then
		return Duel.IsExistingMatchingCard(s.cfilter, tp, LOCATION_MZONE, 0, 1, nil)
	end
end
function s.lvfilter(c)
	return c:IsFaceup() and c:IsAttribute(ATTRIBUTE_WATER)
end
function s.lvop(e, tp, eg, ep, ev, re, r, rp)
	local c = e:GetHandler()
	if c:IsRelateToEffect(e) then
		local lv = Duel.GetMatchingGroupCount(s.lvfilter, tp, LOCATION_MZONE, 0, nil)
		local g = Duel.GetFieldGroup(tp, LOCATION_MZONE, 0)
		local mg, fid = g:GetMaxGroup(Card.GetFieldID)
		local e1 = Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_FIELD)
		e1:SetCode(EFFECT_UPDATE_LEVEL)
		e1:SetRange(LOCATION_FZONE)
		e1:SetTargetRange(LOCATION_MZONE, 0)
		e1:SetTarget(s.efftg)
		e1:SetValue(lv)
		e1:SetLabel(fid)
		e1:SetReset(RESET_EVENT + RESETS_STANDARD + RESET_DISABLE + RESET_PHASE + PHASE_END)
		c:RegisterEffect(e1)
	end
end
function s.efftg(e, c)
	return c:GetFieldID() <= e:GetLabel() and c:IsAttribute(ATTRIBUTE_WATER) and c:GetLevel() > 0
end

