If you have five hearts, you can use sword beam. (zeldadungeon.net)
The second is the is the Fierce Diety Armor that allows you to do sword beams in 4 directions and increases your attack power. (nintendo-okie.com)
Along the same lines, some colossi can be a bit tough to find when they are hidden in an underground temple and your sword beam doesn't do the best job of directing you to the entrance. (videochums.com)