Incognito and the Anime-Original Endgame
SPOILER!
Episodes 9–13 · 2001 GONZO Continuity
The 2001 anime begins separating sharply from the unfinished manga material and builds its own final enemy in Incognito. The FREAK-chip investigation, compromised British forces and the attack on Hellsing all converge on an occult endgame at the Tower of London. Incognito belongs specifically to this television continuity, which is exactly why he matters here: he is the answer GONZO created when thirteen episodes needed an ending before the manga had one.
Yasushi Ishii's Sound Is Half the Identity
2001 TV · Raid (2001) · Ruins (2002)
Yasushi Ishii's score gives the 2001 Hellsing anime a personality no later adaptation simply replaces. Garage rock, jazz, blues, distorted guitar and long stretches of cool restraint sit underneath violence that could easily have become generic gothic action. The soundtrack albums Raid and Ruins arrived around the original broadcast, and the music remains one of the fastest ways to identify exactly which Hellsing somebody means.
Section XIII Iscariot in the 2001 Series
Episodes 3 & 7 · Alexander Anderson
The Vatican's Section XIII Iscariot is Hellsing's Catholic counterpart and rival, introduced through Alexander Anderson rather than through a giant later-franchise war. In the 2001 series, the conflict is personal and institutional: both organizations hunt monsters, both believe they have divine or national authority to do it, and neither accepts the other's methods. Anderson makes that rivalry physical every time he meets Alucard.