Suppressed presence with 〜た+つもり
Grammar Explanation: Speaker's conviction with 〜た+つもり

While changing into her uniform, Rize hid in the closet when she sensed someone unfamiliar nearby. Cocoa, feeling as though she was being watched, opened the closet door.
- ココア:
- 「下着姿
( の…ドロボーさん?」- “A burglar… in their underwear?”
- リゼ:
- 「完全
( に気配( を殺( してたつもりなのに」- “I thought I completely suppressed my presence, and yet...”
Key Points
〜たつもり shows Rize’s belief about what she had done
In 気配
( を殺( してたつもり, Rize means she thought she had successfully hidden her presence.The pattern looks back on something the speaker believes was already true or already done.
してた is casual していた
殺
( してた is the spoken contraction of 殺( していた.
気配
( を殺( す means to suppress your presenceHere 殺
( す is not literal killing. In this expression, it means to erase or suppress signs of oneself.完全
( に strengthens the claim, so Rize thought she had hidden herself completely.
なのに marks the failed expectation
なのに means “and yet” or “even though”, showing that the result does not match Rize’s expectation.
Cocoa opening the closet proves Rize’s confidence was wrong, which is why つもりなのに fits the scene.