Found a strategy that got me through the final boss! ROT13 if anyone wants to know, spoilers etc:
Gur pyrnare'f qnzntr bire gvzr orpbzrf n zhpu ovttre qrny nf gur onggyr cebterffrf naq gur obff fgnegf trggvat zber gheaf. V haqrerfgvzngrq vg, V'q orra sbphfrq ba qrnyvat nf zhpu qnzntr nf cbffvoyr jvgu gur naqebvqf naq xrrcvat gurve ZC gbccrq hc, V sbetbg gb whfg qb erthyne nggnpxf. Gur 14-15 qnzntr zhygvcyr gvzrf cre ebhaq ernyyl fgnegf gb nqq hc, naq lbh pna sbphf zber ba xrrcvat rirelbar nyvir.