Brachioraidos is hard. :( (FFIV Advance - Spoilers abound)

[vm`]

I've beaten this enemy 4 times now with this method. After two failed attempts I noticed something with his attack patterns and found this to be an easy way to win.

Once you have done so much damage to it, the countdown starts and from there onwards he tends to only use the triple-magic attacks, so here's a trick I found. If you lose a party member, revive them immediately with only a phoenix down. Do not use an elixir or cure them in any way because the triple-magic attack will happen soon after and you will have just wasted the elixir/mp. So, instead just keep physically attacking and reviving with phoenix down asap. As long as you always have at least 4 people alive then this should work since that triple magic attack usually kills the other 3. I did this only with average level of 55 for the whole party the first time using this strategy.

It works with any given party for me, but here's what I use for attacks.

Cecil/Cid/Edward - Physical Attacks
Rosa/Porom - Cast Holy, use reflect if needed
Edge - Physical attacks or throw fuma shuriken
Yang - Punch/Deadly
Kain - Jump/Dbl Jump
Rydia/Polom - Strong black magic attacks, reflect if needed