how am i supposed to heal or throw potions at princess Garnet when she is trapped by the plant like thing,

Can't you select her seperately from the actual monster...?

you mean by using the triangle button,if i do then what,how do i throw or make her drink potions during the battle
btw i am talking about about the monster who absorbs hp from princess garnet and has her trapped inside him(it is after the ship crashed)

Well, use the direction buttons to change the position. Try different ways and you'll find out..... ;)

just don't hit her but that guy does suck energy from her so try using the direction button and give her potion and by the way at that time you have trance so keep attacking as well as keep using fire magic it should take you 3mins to beat it

lol there are two things i don't understand,how am i supposed to give here potions,and how can i cast the fire spell or fire magic

It's simple, you can select either garnet or the monster, select garnet to give potions to, and the monster to do spells to =/

Hit X to select the potion and then use the left / right arrows on the controller to move a little target indicator you should be seeing between Garnet and the monster. If you play it well, you should only need one potion.

You only need to use the direction buttons.

Hm.

does it matter i didn't use potions i just beat the crap outta the thing and i hadn't leveled up at all.

Not at all. The potions are only if Garnet's in danger and you need to help her out.