Over the weeks leading to Christmas break I worked mainly on dolls and enchantments. However during that time I found a some magic I was particularly good at. I was incredibly powerful when it came to fire and heat magic. I'd always hated the heat but I seemed to have some kind of natural affinity for it. The affinity would probably explain why my body was always more tolerant of different temperatures. Alongside that was affinity for lighting. Not horribly surprising as I was full of tech, bio-electricity from my evolution and having a bit of the force. Last was ice magic. While I wasn't very powerful with it, I was incredibly accurate. I could easily create exactly what I wanted with it.
None of the affinities mattered much besides when I was learning how to create an ice wall or throw lightning. The fire affinity was the most useful as it helped in learning to create and control fiendfyre. Asking the ROR to make a room to learn fiendfyre in gave me a large forest that had a massive river running around it and a small bridge over.
I quickly learned that fiendfyre was a very nasty summoned amortal creature. Powerful ice and water magic came in handy learning how to defend myself against the fire. I eventually figured out that my magic gave it its form and that I could easily shift said form. Shifting the form continuously would turn it into a lump of really angry flames. After a week of messing with it I found that its control method was mostly based on will and intent. Will and intent were easy to train for me as I had learned of some Norse intent based runes and some Indian will based enchantment marks.
With those runes I trained my intent and willpower over the last week till break. The next time I used fiendfyre I could make it turn from a terrifying fire with a Darth Vader like figure within to a small puppy of pure flame. I continued to mess with the spells into the holiday when I suddenly got a commission. I hadn't advertised it but I was willing to make stuff for a price.
Besides the dolls and their materials the school was also covering multiple things for me. Part of the cost was knowledge/information, and the creation of things for the school. I hadn't advertised it because I figured I'd pay the small debt via some dolls and knowledge. However this commission would be easy to do. The astronomy professor wanted good tools for astronomy. I immediately started making basic droids with runes to protect them.
With the droids I took over the astronomy tower. I demolished the tower and quickly rebuilt it with durasteel. On top was a large ball with a telescope poking out of it. Internally it was massively expanded and had many different telescopes and other scientific instruments. Everything was enchanted and the room could be made transparent.
Finally for the last addition to the new tower I added an astromech droid to do anything that was needed in the room. I figured that with this stuff magical astronomy would quite literally jump to space.
After the astronomy tower I helped to update arithmancy, muggle studies, and runes. I also planned to drag Dumbledore into making a new class. As Defense Against the Dark Arts was cursed I figured we could simply make a different class.
The 'Magical Defense Class' would be taught by Flitwick, McGonagall, and Snape on a rotating schedule. These professors would teach the students how to 'defend' themselves with the magic each professor specialized in. Shape of course jumped at the proposal. It was well known that he'd wanted the DADA position and this was probably the closest he'd get to it. Flitwick was the staunchest supporter for the class as he'd had practically been forced to give up most dueling related stuff by the Hogwarts board. Last was McGonagall.
She was the hardest to convince as she already had massive time sinks on her shoulders. Of course I solved those time sinks by modernizing how she did things. With a large amount of her work now made easy she could make time to do this class. With the three at my back I 'forced' Dumbledore to create the class. The class was currently on probation as he still needed to get the board to sign off on it.
This was when I finally dropped back into my true purpose. Malfoy and some board members had gone completely against the class and shot it down. I identified them all and left to Diagon Alley the next day. With the 'help' of multiple peoples in Knockturn alley and some assistance from the goblins I was able to find the homes of all my targets. A large majority of my targets were 'ex' deatheaters, but a few were simply supporters.
The deatheaters were the only ones to give me any challenges as they all put up a bit of a fight. The only truly challenging opponent was Malfoy as his wards withstood a full power fiendfyre. A few, laws of physics breaking, railgun shots later and his mansion was crumbling. I visibly saw Narcissa cast a powerful spell then apparate out. I deployed an experimental anti teleport rune and then engaged Malfoy. With Narcissa having taken Draco and Dobby being a crafty elf I only had to contend with one wizard and one house elf. Malfoy flung lots of nasty spells but was incredibly slow. A large ice wall stopped his attacks as I sent a fiendfyre around the wall at him. The house elf was continually attempting to fling me away or throw fire but is simply swatted the fire and ate the magic blasts head on.
I'd taken my old armor and practically covered it in anti magic runes to the point it was hard to use my own magic. I got tired eventually and simply shot an arm off of the elf. With the elf out of the fight I decided to get some proper magic combat practice in. Spell flinging was slow. Like most duelists of this world I learned multiple wordless, gestureless spells. The lightning spell fulgur and the explosion spell bombarda were easy to use with out wand waving.
After an overpowered reducto destroyed my cybernetic hand augmentation I simply started blasting fiendfyres. With the reintroduction of the fire Malfoy started throwing killing curse. The green beams launched into the night carving small furrows in the earth around me. However fiendfyre was many times more insidious than than a green laser. Without my direction a spark hopped behind Malfoy and lit. It quickly jumped onto his robes as hundreds of small spiders made of magical flame.
I'd heard many horrific things in my two lives but Malfoys dying screams would likely haunt me right alongside all the other nightmares. I fled the moment his burning corpse collapsed into ash and dust. My fiendfyres hunger sated and it died. With Malfoy gone I got back to Hogwarts and used my newly discovered time turner to make myself plenty of alibis.
The only targets of import now was the overly corrupt idiots in the ministry and the one secret deatheater in the department of mysteries.
When I went to bed that night I gave Rena a tight hug. She didn't realize it but she had been a big reason for the nightmares and horrible memories being quieter. As I lay down I remembered an old joke from my first life and I determined that it was true. Is the cure to male loneliness, becoming a single father?