Luin or Selene + the newest update

1. Who would perform better in PvP? Selene or Luin? Both are above 7 stars. 
2. Also, where can I find this?

">Mark Explode True Damage: Specialized against high-defense tanks/resurrection teams, instantly depleting boss HP!

>Max Ability Enhancement: Attribute boosts + 100% mark activation for rapid area clears!

>Star Ascension Awakened: 5-star chasing combo, 7-star awakening unlocks 3-wave burst damage per turn!"