What is up with YGO and mind/body-control/possession?

Greydle Impact

Spell Continuous

You can only use 1 “Greydle Impact” effect per turn, and only once that turn. (1) You can target 1 other “Greydle” card you control and 1 card your opponent controls; destroy them. (2) During your End Phase: You can add 1 “Greydle” card from your Deck to your hand.

Greydle Parasite

Trap Continuous

You can only use each effect of “Greydle Parasite” once per turn. (1) When an opponent’s monster attacks your directly, you can: If you control no monsters, Special Summon 1 “Greydle” monster from your Deck in Attack Position. (2) When a “Greydle” monster you control attacks directly: You can target 1 monster in your opponent’s Graveyard; if your opponent controls no monsters, Special Summon that monster to your opponent’s side of the field.