So my main character in my story, is of a more aristocratic type house. Not necessarily in attitude, but in theme. So victorian style long coats and vests etc, while also being rogue/thief information gathering types, think assassin's creed 2.My question is mainly that I would like him to use an Estoc style weapon, thin, long thrusting sword. Normal fencing is very much at odds with the fighting style I would like him to have, fast, acrobatic, mobile, low, high, basically attacking from all angles with reflexes and precision to match. The issue is coming up of thinking up say low floor level attacks and the blade being too long to position well without hitting the floor, or if there needs to be dodge rolls or flips or any other movements in which a long blade is already an annoyance, is there a fighting style in existence that looks more like this, a type of ninja like or more animalistic on the fly fencing/thrusting, or what are some suggestions on how to make this work?
Modern Fencing is Not Historic Fighting
I am a Historic European Martial Artist, and modern sport fencing is not the same as what was actually performed. They stay on line, you cannot grab blades, the area is perfectly flat, there are illegal actions, and there are rules to make it a sport of blade feeling, reaction time, and speed. That's all well and good, but it is not the only thing to fighting.
How do I know what was actually performed? I am so glad you asked! In addition to historical accounts, we have treatises in various languages from WWII knife fighting manuals all the way back to the early medieval period sword-and-buckler! Check out the free resource of wiktenauer.
Fighting Was Already Dynamic
The truth is that historic fighting is intense, totally capable of engaging every capacity and sense a human has. It already has so much of what you are looking for. I know this because I have practiced it.
Fighting was also very dynamic. It is general advice and practice to hit people from multiple angles (see the Meyer Square Drill) while moving around them. Yes, the Meyer Square drill usually does cuts, but you can also mix thrusts in! Other systems offer similar advice. You see this in most HEMA tournaments, which you can readily see on YouTube. (Try "Swordfish tournament" for a well known one.)
Better yet, you can go to the HEMA alliance page and find a local club. Local clubs may have introduction classes which will give you more than you need to write a good European swordfighter from any time period. The longsword (or "hand-and-a-half-sword") is a gateway weapon: if you understand it, you can reasonably use a lot of other weapons.
What You Do Not See
You will not see rolling, diving, or spinning on anything like a regular basis. These are bad, bad, bad options in combat! They take too long, remove your ability to defend, and prevent you from seeing what your opponent does!
Put simply: rolls, dives, and spins are mostly suicidal. While your butt is in the air because you elected to perform a dive-roll, your opponent will slice you open and thank their lucky stars for such a foolish opponent. In rare circumstances, it may work, but it's a once-in-a-lifetime thing. (Especially when it fails.)