Blood of the Legion is a companion perk in Fallout: New Vegas.
Requirements[]
Gaining this perk requires talking to Doctor Henry during Nothin' But a Hound Dog about replacing Rex's old brain with a new one and following the option of finding a Legion mongrel with a suitable brain. This is accomplished by going to The Fort and talking to Antony. He typically stands near the arena next to Lupa.
To obtain Lupa's brain, Antony requests that the player character fight against her in the arena, to give her an "honorable death". The fight follows the typical rules of the arena: no gear except for gladiator armor and a machete. Upon killing Lupa, her brain can be taken.
Effects[]
When Rex is an active companion, he gains an additional 10 points of DT.
Notes[]
Prior to patch 1.2.0.31x, Blood of the Legion gave Lupa +100 HP instead.