Flash - Advent: [During Advent] (Your Turn) By sending Soul Core to your Trash, stack this from your hand onto your target spirit.
[During Advent][LV1][LV2][LV3] (Your Attack Step) When the opponent uses a Magic card or Accel effect, before the effect resolves, by placing 1 card from your hand from the "Ancient Dragon" family as a pre-Advent card under this spirit, negate that effect of that Magic Card/Accel effect.
[LV2][LV3] Flash- Twinkle Dragonic Dominance (When Attacks) By summoning 1 pre-Advent card with the name "Siegfried" under this Spirit without paying it's cost, move 1 core from the opponent's life to their reserve.
Rulings:
1. As its effects only state "cards" instead of "Spirit cards", Ultimates can also be added as pre-Advent cards and summoned.
2. As its effects targets "Ancient Dragon" and 'summons pre-Advent', since Nexuses don't have families and are 'deployed' instead of 'summoned', they can't be used.