Havel's Ring
Havel's Ring boosts your maximum equip load, allowing you to equip a heavier weapon and/or armour set while remaining below 70% weight ratio. The ring is useful whenever you want to equip a decent armour set to help you tank one or two hits from a boss while you learn the boss' attack patterns. The ring will be used to help you grab Toxic Mist.
Curse-rotted Greatwood
SL1 Curse-rotted Greatwood, Dark Souls III
This boss is weak against fire. Buff your Raw Broadsword+10 with Charcoal Pine Resin/Bundle. Prior to triggering the fight, defeat the various Peasant Hollows within the arena. Two-hand the Broadsword to help you attack the boss' various sacs.
Defeat the Curse-rotted Greatwood to obtain the Transposing Kiln. Give the Kiln to Ludleth and he would be able to transpose boss souls into weapons.
Farron Keep
Start from the Old Wolf of Farron bonfire. Ride the elevator up to find the Stray Demon.
Stray Demon
SL1 Cheese the Stray Demon, Dark Souls III
Lure the boss to the staircase and use ranged weapons to cheese it. The boss can be dangerous to fight head on. It can grab your character and throw you off the cliff.
Defeat the Stray Demon to obtain the Soul of a Stray Demon. Transpose this soul with Ludleth for Havel's Ring.