Pendulum Effect
If a monster(s) is Special Summoned and you control "Supreme King Z-ARC" and another Pendulum Monster (except during the Damage Step): You can Special Summon this card, then you can make the Level and Attribute of either this card or 1 Pendulum Monster you control become the same Level and Attribute as the other. You can only use this effect of "Supreme King Dragon Lightwurm" once per turn.
Monster Effect
If this card is Normal or Special Summoned: You can add 1 face-up "Supreme King Dragon" or "Supreme King Gate" Pendulum Monster from your Extra Deck to your hand, then, immediately after this effect resolves, you can Synchro or Xyz Summon 1 "Supreme King Dragon" monster. If a face-up Pendulum Monster(s) you control is destroyed by battle or card effect, while this card is face-up in your Extra Deck: You can add this card to your hand. You can only use each effect of "Supreme King Dragon Lightwurm" once per turn.