With Invasive Surgery, ordinarily you have a one-drop counterspell specifically targeting only sorceries. This is similar to Dispel which targets only instants. But with Delirium active, not only do you get to counter a sorcery spell, but you get to search that player's graveyard, hand, and library for any other cards with the same name and exile them.
While this card is a bit on the situational side, we've seen the power of cards like Surgical Extraction and Infinite Obliteration that have this sort of ability. Limited to only sorceries, though, Invasive Surgery is a bit narrow. Still, Delirium is a cool mechanic that if set up correctly could provide some extremely powerful benefits for those casting them.