Tanzra, also known as "The Evil One", is the Master's enemy and the primary antagonist.
Tanzra appears in Death Heim, after the Master has carved his way through all of the Act-2 Guardians for a second time. Tanzra has two forms, and the Master will auto-equip the Flame Sword for this conflict.
Tanzra's first form is that of a floating head. His second form is that of a skeletal undead creature, with a pulsating blue heart.
The head will phase slightly out, becoming invincible, as it casts it's own version of Magical Stardust. The head will then fall to the ground, belching out damaging projectiles, then appear above and repeat the pattern. Though the head makes for a small target, the Master's own Magical Stardust can cause serious damage if he gets lucky when the head's not invincible. It's much easier to engage in melee, waiting until Tanzra's head within striking distance of his sword beams; two solid series of slashes should finish it off.
Tanzra's second form is much tougher and has a variety of attacks. He also has double the life bar of any other boss.
- Fireball: Tanzra will raise a palm and shoot three pairs of fireballs, above and below. When the Master is between the fireballs, they'll immediately fly vertically towards him. If he's still moving when they change direction, they'll generally miss. The problem is getting enough space to clear all three pairs.
- Seeking Sparks: Tanzra will belch two pair of sparks, red and blue. These sparks will make quick, halting movements towards the Master, quickly re-orienting themselves to his current position. They can be destroyed in a single slash, but they often come at odd angles that make them difficult to hit.
- Core Bolt: Tanzra will remove the shielding from his vile heart, and fire a bolt of damaging energy forward. This is the only opportunity for the Master to damage Tanzra, and it's only efficient to do so with the Flame Sword's crescent beams.
In Actraiser 2, Tanzra returns along with his demonic troops.
This time, he is encased in ice while fighting with the Master. Therefore, he has limited mobility, but his size makes up for this.
A secret code in ActRaiser 2 pits you against Tanzra's forms from the first ActRaiser. The battle now is considerably harder since the Master is much slower in this game.
- In the Japanese version of ActRaiser, Tanzra was called "Satan". To avoid religious references, they changed this to Tanzra in the US and PAL releases.
- At the end of ActRaiser 2, Tanzra is fought as a giant beast waist-deep in ice. This is most likely a reference to Satan's condition in Dante's Inferno of the Divine Comedy.