Lich
If you Tribute Summon this card, the Tribute must be DARK. If this card is Tributed by a card effect and sent to the GY: Add this card from your GY to your hand.
local s, id, o = GetID()
function s.initial_effect(c)
	--tribute limit
	local e1 = Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_TRIBUTE_LIMIT)
	e1:SetValue(s.tlimit)
	c:RegisterEffect(e1)
	--to hand
	local e2 = Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id, 0))
	e2:SetType(EFFECT_TYPE_SINGLE + EFFECT_TYPE_TRIGGER_F)
	e2:SetCode(EVENT_RELEASE)
	e2:SetCondition(s.retcon)
	e2:SetTarget(s.rettg)
	e2:SetOperation(s.retop)
	c:RegisterEffect(e2)
end
function s.tlimit(e, c)
	return not c:IsAttribute(ATTRIBUTE_DARK)
end
function s.retcon(e, tp, eg, ep, ev, re, r, rp)
	return e:GetHandler():IsLocation(LOCATION_GRAVE) and e:GetHandler():IsReason(REASON_EFFECT)
end
function s.rettg(e, tp, eg, ep, ev, re, r, rp, chk)
	if chk == 0 then
		return true
	end
	Duel.SetOperationInfo(0, CATEGORY_TOHAND, e:GetHandler(), 1, 0, 0)
end
function s.retop(e, tp, eg, ep, ev, re, r, rp)
	local c = e:GetHandler()
	if c:IsRelateToEffect(e) then
		Duel.SendtoHand(c, nil, REASON_EFFECT)
		Duel.ConfirmCards(1 - tp, c)
	end
end


Lich
If you Tribute Summon this card, the Tribute must be DARK. If this card is Tributed by a card effect and sent to the GY: Add this card from your GY to your hand.
-- Lich
local s, id, o = GetID()
function s.initial_effect(c)
	--tribute limit
	local e1 = Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_TRIBUTE_LIMIT)
	e1:SetValue(s.tlimit)
	c:RegisterEffect(e1)
	--to hand
	local e2 = Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id, 0))
	e2:SetType(EFFECT_TYPE_SINGLE + EFFECT_TYPE_TRIGGER_F)
	e2:SetCode(EVENT_RELEASE)
	e2:SetCondition(s.retcon)
	e2:SetTarget(s.rettg)
	e2:SetOperation(s.retop)
	c:RegisterEffect(e2)
end
function s.tlimit(e, c)
	return not c:IsAttribute(ATTRIBUTE_DARK)
end
function s.retcon(e, tp, eg, ep, ev, re, r, rp)
	return e:GetHandler():IsLocation(LOCATION_GRAVE) and e:GetHandler():IsReason(REASON_EFFECT)
end
function s.rettg(e, tp, eg, ep, ev, re, r, rp, chk)
	if chk == 0 then
		return true
	end
	Duel.SetOperationInfo(0, CATEGORY_TOHAND, e:GetHandler(), 1, 0, 0)
end
function s.retop(e, tp, eg, ep, ev, re, r, rp)
	local c = e:GetHandler()
	if c:IsRelateToEffect(e) then
		Duel.SendtoHand(c, nil, REASON_EFFECT)
		Duel.ConfirmCards(1 - tp, c)
	end
end

