Play PvP, improve at the game significantly in half the time.
No it isn't, its an incredibly good sword. Realistically it should be moved away from before Sens Fortress but up until then it kicks the ass of nearly everything else you can get without a load of farming but for Stray its fine.
The thing with the Souls games is that you have two choices, take it seriously or don't. The majority of players do not and as a result they get stuck on bosses for hours on end, this is neither a problem nor a "wrong" way to play, however it is a consequence most have to deal with.
Neither Demon's Souls nor Dark Souls are particularly hard games, they are unforgiving games yes but the mechanics and mathematics of them aren't "that" deep. Information is a key to success, the more you know the better you will do, the rest is just muscle memory such as how well you recognise/remember telegraphs.
Case in point Stray Demon, high health, deals fire damage and uses highly telegraphed forward facing AoE attacks which extend slightly behind him as his primary attacks. Response? Stay behind him and move in and out between blasts, equip fire resistance and long range melee weapons ideally, if unsure about dodging AoE even if behind him, equip high poise armour and high fire resist shield to block damage without being stunned. Going to be dodging a lot? Consider DoT damage such as Bleed or Poison to reduce the duration of the fight.