Rainbow
If a monster(s) you control whose original name is "Rainbow Dragon" or "Rainbow Dark Dragon" activated its effect this turn: Special Summon any number of "Crystal Beast" monsters with different names from your Deck.
local CARD_ID_0 = 59822133 --Blue-Eyes Spirit Dragon
local CARD_ID_1 = 79856792 --Rainbow Dragon
local CARD_ID_2 = 79407975 --Rainbow Dark Dragon
local SETCARD_ID_0 = 0x1034 --Crystal

local CARD_ID_0 = 59822133 --Blue-Eyes Spirit Dragon
local CARD_ID_1 = 79856792 --Rainbow Dragon
local CARD_ID_2 = 79407975 --Rainbow Dark Dragon
local SETCARD_ID_0 = 0x1034 --Crystal
local s, id, o = GetID()
function s.initial_effect(c)
	--Activate
	local e1 = Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetCondition(s.condition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
	Duel.AddCustomActivityCounter(id, ACTIVITY_CHAIN, s.chainfilter)
end
function s.chainfilter(re, tp, cid)
	return not (re:IsActiveType(TYPE_MONSTER) and re:GetHandler():IsOriginalCodeRule(CARD_ID_2, CARD_ID_1))
end
function s.condition(e, tp, eg, ep, ev, re, r, rp)
	return Duel.GetCustomActivityCount(id, tp, ACTIVITY_CHAIN) ~= 0
end
function s.filter(c, e, tp)
	return c:IsSetCard(SETCARD_ID_0) and c:IsCanBeSpecialSummoned(e, 0, tp, false, false)
end
function s.target(e, tp, eg, ep, ev, re, r, rp, chk)
	if chk == 0 then
		return Duel.GetLocationCount(tp, LOCATION_MZONE) > 0 and Duel.IsExistingMatchingCard(s.filter, tp, LOCATION_DECK, 0, 1, nil, e, tp)
	end
	Duel.SetOperationInfo(0, CATEGORY_SPECIAL_SUMMON, nil, 1, tp, LOCATION_DECK)
end
function s.activate(e, tp, eg, ep, ev, re, r, rp)
	local ft = Duel.GetLocationCount(tp, LOCATION_MZONE)
	if ft <= 0 then
		return
	end
	if Duel.IsPlayerAffectedByEffect(tp, CARD_ID_0) then
		ft = 1
	end
	local g = Duel.GetMatchingGroup(s.filter, tp, LOCATION_DECK, 0, nil, e, tp)
	if g:GetCount() == 0 then
		return
	end
	Duel.Hint(HINT_SELECTMSG, tp, HINTMSG_SPSUMMON)
	local sg = g:SelectSubGroup(tp, aux.dncheck, false, 1, ft)
	Duel.SpecialSummon(sg, 0, tp, tp, false, false, POS_FACEUP)
end


Rainbow
If a monster(s) you control whose original name is "Rainbow Dragon" or "Rainbow Dark Dragon" activated its effect this turn: Special Summon any number of "Crystal Beast" monsters with different names from your Deck.
-- Rainbow
local CARD_ID_0 = 59822133 --Blue-Eyes Spirit Dragon
local CARD_ID_1 = 79856792 --Rainbow Dragon
local CARD_ID_2 = 79407975 --Rainbow Dark Dragon
local SETCARD_ID_0 = 0x1034 --Crystal
local s, id, o = GetID()
function s.initial_effect(c)
	--Activate
	local e1 = Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetCondition(s.condition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
	Duel.AddCustomActivityCounter(id, ACTIVITY_CHAIN, s.chainfilter)
end
function s.chainfilter(re, tp, cid)
	return not (re:IsActiveType(TYPE_MONSTER) and re:GetHandler():IsOriginalCodeRule(CARD_ID_2, CARD_ID_1))
end
function s.condition(e, tp, eg, ep, ev, re, r, rp)
	return Duel.GetCustomActivityCount(id, tp, ACTIVITY_CHAIN) ~= 0
end
function s.filter(c, e, tp)
	return c:IsSetCard(SETCARD_ID_0) and c:IsCanBeSpecialSummoned(e, 0, tp, false, false)
end
function s.target(e, tp, eg, ep, ev, re, r, rp, chk)
	if chk == 0 then
		return Duel.GetLocationCount(tp, LOCATION_MZONE) > 0 and Duel.IsExistingMatchingCard(s.filter, tp, LOCATION_DECK, 0, 1, nil, e, tp)
	end
	Duel.SetOperationInfo(0, CATEGORY_SPECIAL_SUMMON, nil, 1, tp, LOCATION_DECK)
end
function s.activate(e, tp, eg, ep, ev, re, r, rp)
	local ft = Duel.GetLocationCount(tp, LOCATION_MZONE)
	if ft <= 0 then
		return
	end
	if Duel.IsPlayerAffectedByEffect(tp, CARD_ID_0) then
		ft = 1
	end
	local g = Duel.GetMatchingGroup(s.filter, tp, LOCATION_DECK, 0, nil, e, tp)
	if g:GetCount() == 0 then
		return
	end
	Duel.Hint(HINT_SELECTMSG, tp, HINTMSG_SPSUMMON)
	local sg = g:SelectSubGroup(tp, aux.dncheck, false, 1, ft)
	Duel.SpecialSummon(sg, 0, tp, tp, false, false, POS_FACEUP)
end

