for the guy before me asking bout the sworf: Varangian Sword or something along those lines. Am using it on my knight.
Now the Pursuer and bos fights in general:
Leason 1: Learn to adapt. Think about the boss you face and decide what you should focus on
To ilustrate: The Pursuer is one of the best examples of a boss that can be beaten with both types of builds: fast and tanky (talking as a mele fighter as that was what the OP had problems with). Fast builds should have lower than 50% equipment load with an armour as protective as posible (this depends alot on your own weight limitations so there is no dedicated set for this) and a SMALL SHIELD for parying at first, then when wight allows it a greatshield because of its stability (honestly IDK what medium shields are for ... they offer neither the speed of lights when parying nor the stability of greatshields when blocking ... jacks of all masters of none). The most important thing is having the long dodge and mastering it. The fast build excels versus large hulking bosses that can easily crush your guard (Old Iron King, Freja, Rotten ... the sort) and also versus tag teams (Sentinels, Gargoyles, Pursuer NG+)
Tanky builds: Go all out. Fuck the weight limits and get the heaviest most protective tin can you can find and the biggest most badass greatshield you can get. You won't dodge as much as circle your foes blocking their every hit and getting in a few hits yourself when stamina allows it. And laugh as they don't even damage you. Tanky builds can dodge but you will mostly use it if you PvP with them to prevent a pesky backstab. I also recomend a spear or halebard with this build as it's attacks are short and you can easily recover from them plus they give you reach (axes work well too but with short range). Boses bulnerable to this are mostly the humanoid ones (Old Dragonslayer, Lost Sinner, Dragonrider, Flextile Sentry) because boses never go for the backstab.
The ideal state of the mele character is one where he can keep his heavy tanky armour and his long dodge, but that needs alot of grinding to happen.
Leason 2: Study the boss
Obvious, I know. But did you ever go into a boss fight and spend a minute without atempting any attack what so ever and watching just what the boss likes to do against you? You may be shocked how usefull that can be if you plan to solo (also if you are soloing join the Champions covenant, it helps imensly to force you to learn).
Leason 3: Pick you weapon smartly
Don't just look at the damage value of the weapon. As a veteran I can tell you this: damage is 25% of the weapon, move set if the rest. Go in Majula and see how you move with each weapon, how fast you swing, what types of swings and hits it uses. Pick a move set that suits YOU and one that exploits your enemy: some have long recovery times, others only give you seconds to hit them then you need to go back on the defensive. Some of the fastest, most usefull weapons for this are halebards, spears, reapers, normal swords (curved and straight) and katanas.
Also consider what each boss is vulnerable to (reading a wiki on elemental weakneses isn't shamefull. Beyond that the algorithm is simple: heavyly armored and/or metalic? Lightning; Organic corpse or animal? Fire; In doubt and clearly not an arcane/poison boss? Use magic or poison. Usefull for all? Enchant mundane and get 40/40 str/dex.
Leason 4: How to deal with congregations
When the boss has his retinue of little creatures with him, just ignore the boss and wipe our the smaller creatures. Believe me, this will save you alot of pointless deaths.
Leason 5: Calm, patience and focus trump adrenaline and greed.
Keep calm, focused and don't let the adrenaline and greed make you take unecesary rinsks. You are not under a time limit. So just take your time.