In one respect I’ll thy assistant be; for this alliance may so happy prove to turn your households’ rancour to pure love. (2.3.87-92)
The Friar changes from being worried about Romeo’s feelings to just wanting to be the hero by uniting the two houses. The Friar said : In one respect I’ll thy assistant be. (2.3.90) He wants to assist Romeo, mainly though he just wants to be the one who stops the bloodshed and have power. Marrying the couple causes a bunch of other problem to arise. Tybalt’s death and Romeo’s banishment came about because Romeo and Tybalt were now kin. The Friar is to blame because he married Romeo and Juliet which raised a whole bunch of controversial issues.
The Friar’s ideas were way too complex and unnecessary, it left plenty of room for error. When Juliet is telling the Friar her dilemma, and he comes up with his “genius” plan he says:
If; rather than to marry county Paris, thou hast the strength to slay thyself, then is it likely thou wilt undertake, a thing like death to chide away this shame, that cop’st with death himself to scape from it; and if thou dar’st, I’ll give thee