If a monster is destroyed by battle, it will be sent to the GY only at the end of the Damage Step, not during damage calculation or immediately after damage calculation
This deck also struggles against strategies that can consistently generate advantage, as its endboard is quite weak with only 3 seperate pops, 1 book of moon, 1 monster negate, and 1 monster pop + negate effects with same name, meaning even cards like Raigeki can easily counter it.
No conditions, no extra cost
PGR Premium Gold Rare The Phantom Knights of Rusty Bardiche X DARK Link 3 [ WarriorLinkEffect ] ATK 2100 DEF - 2+ DARK monsters During your Main Phase: You can send 1 "The Phantom Knights" monster from your Deck to the GY, then Set 1 "Phantom Knights" Spell/Trap directly from your Deck to your Spell & Trap Zone
SE Secret Rare Pressured Planet Wraitsoth X SPELL Field When this card is activated: You can add 1 "Kashtira" monster from your Deck to your hand