Umbral Horror " Umbral Horror " , known as " Umbral " ( アンブラル " Anburaru " ) in the " OCG " , is an archetype used by Vector in the " Yu - Gi - Oh ! ZEXAL " anime . It is composed mostly of weak DARK Fiend monsters who revolve around Special Summon ing other " Umbral Horror " monsters for quick Xyz Summon s . " Umbra " means " shadow " , and comes from the Latin word of the same spelling . Strengths . " Umbral Horrors " have unique abilities to quickly swarm the field to allow for quick Xyz Summons . Their DEF at 0 also make them an ideal target for cards such as " Masked Chameleon " , " Secret Sect Druid Dru " , that can revive most of them from the Graveyard at the expense of having their effects negated . However this can also allow for successive and constant Summons of Rank 4 Xyz monsters and Level 5 or Level 8 Synchros , thus being capable of Summoning powerful monsters with ease . " Recurring Nightmare " can be used with the " Umbral Horror " monsters , principally " Umbral Horror Ghoul " or " Druid Dru " and another " Umbral Horror " for an instant Rank 4 monster . Cards such as " Allure of Darkness " can be used easily for draw power . Furthermore considering the 0 ATK nature of " Umbral Horrors " , including " Ghoul " through its own effect , " Reptilianne Vaskii " can be Summoned with ease , allowing potent field control through its effect . Because of their effective ways to Summon Rank 4 monsters , one can afford Rank - Up plays with the Deck . Also if one uses the effect of " Umbral Horror Unform " , it is entirely possible to Xyz Summon a Rank 4 that requires 3 materials with relative ease , and through Rank - Up one can easily Summon powerhouses such as " " , " " and its evolved form " " and also " " and " " for massive field control and brutal damage potential . Due to the lack of internal support and their own boss ( bar perhaps " Number 104 " ) , Umbral Horror Decks tend to have small restrictions on their deck building . Therefore one can place pretty much as many techs of their preference as they want , without hindering them too much . The same is true for their Extra Deck , being capable of running almost any and all generic Rank 4 Xyz Monsters and Level 8 Synchro Monsters , thus the player can have as many options as they want to incorporate for any situation , making the deck incredibly versatile on its plays and responses . Weaknesses . As explained above , " Umbral Horrors " have low ATK and DEF , rendering them quite weak by themselves and thus likely to be destroyed . Furthermore effects such as that of " Umbral Horror Unform " needs it to ram itself into an opponent ' s monster , thus likely causing a substantial damage to one ' s Life Points . Most of the external support such as " Masked Chameleon " , " Druid Dru " , " Debris Dragon " , and " Recurring Nightmare " focus exclusively on the Graveyard ; therefore , cards that block the Graveyard such as " Necrovalley " , " Macro Cosmos " , or " Dimensional Fissure " can be downright fatal to the Deck . All " Umbral Horror " monsters and " Druid Dru " are DARK , so cards such as " Shadow - Imprisoning Mirror " can block all of those monsters , leaving few options available . Cards that prevent effects such as " Skill Drain " can easily block " Masked Chameleon " , " Druid Dru " , and " Debris " , thus preventing any revival plays from those monsters . " Chain Disappearance " can annihilate most " Umbral Horrors " and render them useless through banishing . " Doom Donuts " can also be used against " Umbral Horrors " , although it is more of a short - term annoyance rather than a definitive threat .