LionHeartKIng Wiki
LionHeartKIng Wiki

A Nucleo Monster is a type of Monster Card introduced by HelixReactor. They are stored in the Extra Deck.


In appearance, Nucleo cards look very similarly to Pendulum Monsters. Instead of having a Pendulum Scale value on both extremities of their top effect box, Nucleo Monsters have a single indicator for their Base at the left extremity of their top effect box, which will be used for their Base Effect. Color-wise, they have a salmon pink border color, with a blue horizontal stripe in the middle of the card.

Materials recovery[]

When a Nucleo Monster leaves the field, the Nucleo Materials that were attached to it are returned to their location prior to being used as such.

In the case of a Nucleo Monster being used as a Nucleo Material, then if the newly summoned Nucleo Monster leaves the field, the former Nucleo Monster returns on the field with its former Nucleo Materials attached to it (as long as those Materials haven't been used, of course).

In the case of a Nucleo Monster with Nucleo Materials being used as a Nucleo Material then detached, then the newly summoned Nucleo Monster leaves the field, Nucleo Materials that were initially attached to the former Nucleo Monster are sent to the Graveyard.


As stated above, Nucleo Monsters have a unique indicator called Base, which can be considered as an additional Typing. Nucleo Monsters can have one between 5 Bases, each names after a nucleobase: Adenine, Thymine, Cytosine, and Guanine, and Uracil.

Base Effect[]

A Nucleo Monster's effect box is split into two: A Standard Effect, and Base Effect. The Standard Effect is equivalent to the ordinary effect every Effect Monster has. The Base Effect, on the other hand, has a wider range, as multiple monsters of the same Base: When a player controls a Nucleo Monster, all other Nucleo Monsters they control that have the same Base can use that monster's Base Effect as their own.

In this context, the Uracil Base acts like a Joker, as it can use the Base Effects of all Nucleo Monsters on its side of the field, and share its own Base Effect with every Nucleo Monster on its side of the field.

It is important to note that multiple copies of the same Base Effect do not "stack". Meaning that, for example, a players has two copies of the same Nucleo Monster that has a "once per turn" Base effect, each compatible Nucleo Monster can only activate that Base effect once, and not twice.

Keep in mind that, if a Nucleo Monster's effects are negated:

  • It can neither use its Standard and Base Effects, nor other Nucleo Monsters' Base Effects.
  • Other Nucleo Monsters on the same side of the field can still use the negated monster's Base Effect.

In order to prevent a Base Effect from being used by any monster at all, that effect needs to be erased.

Other terms[]


Two Nucleo Monsters are said to be compatible if both of them have the same Base, or if either of them is a Uracil-Base.


Erase is a term related to Nucleo Monsters, similar to negating. As stated above, when a Nucleo Monster's Base Effect is erased, than neither it or other Nucleo Monsters on the same side of the field can take profit from that Base Effect.


A Base Effect's Origin (or Origin for short) is a Nucleo Monster who has a given Base Effect printed on its card.


See also[]