SPOILERS ARE WITHIN THE POST
In Elden Ring, during the last stages of Bernahl, a knight clad in ferocious armour and member of a secret order of assassins of the clandestine Volcano Manor, makes a solemn pledge against the omniscient presence known as the Great Will, the English lines are:
O Greater Will, hear my voice. I am the recusant Bernahl, inheritor of my brother's will, and you will fall to my blade.
We refuse to become your pawns. Consider this fair warning.
Compared with the Japanese lines in the original:
… Ooinaru ishi yo, kiku ga yoi
Waga na wa hairitsusha Berunâru. Tomo no ishi o tsugi, omae o tsubusu
Warera wa omae no koma narazu. Sore o omoishirasete yaru
"O Great Will, hear me.
My name is Bernahl, the Defier of the Order.
Continuing the dying wish of a friend, I shall crush you.
We shall not become your game-pieces. This shall I make you realise."
Thus two things are apparent, one is that the title of order of Assisins, The Defiers of the Law, called "the Recusants" in the English localisation, is using an old term for someone who in historical usage refused to attend the services conducted by the Anglican Church during Elizabethan times, here it is used to translate a term referring to them "defying/turning their back" (背, se) towards the "Order/Law" (律, ritsu).
Secondly, Bernahl is referring to friend, or a brother-in-arms, rather than a genetic relation, as is ambiguously the case in the English version. Here it is tomo (友, "friend"), a term that unequivocally means "friend" or more technically "dear non-familial relation."
Had he meant brother it would have been terms such as kyoudai (兄弟, "brother(s)"), which in itself is an age-neutral term and can refer to both younger and elder brothers.
Thus, he is swearing vengeance against a godlike figure to fulfill the dying wish of his compeer, rather than that of a family member.
Furthermore, if we go in further detail with the line inheritor of my brother's will, and compare it to the Japanese line, tomo no ishi o tsugi, we get slight differences and nuances in meaning, apart from brother and tomo differing, we have the key term ishi no tsugi:
Lit. Dying-wish genitive-particle Successor/Heir
The first term 遺志 (ishi, lit. "bequeath-intention") is used for a "dying wish" or the "wishes of a decased person," the next term 継ぎ (tsugi, "inheritor/successor/heir"), is literally a noun form of the verb 継ぐ (tsugu, "to succeed a person/position, to inherit a position/thing, to take over, to follow") and thus have various meanings, but all relating to the personal act of continuance of a thing or position.
The entire expression however is also ideomatic referring to fulfilling someone's dying wish.