Here are some tips to help with the last two boss battles in the game. Use them if you're stuck ^_^

If you're having SP problems, check out the Weapons and Armor sold by the Merchant Android in the Safe Room. She sells an expensive accessory called the Pocket Reactor that cuts SP use in half. By now you should have nearly enough Creds to afford it.

If you got Maelym's Vim Vapor move in the North Caves, you can use it to greatly boost someone's damage output on the final battles. Maelym or LR-338 are good choices.

On the second-to-last battle, try to take out Khain or RX-779 first, as they have punishing attacks, especially RX-779's hit-all abilities. Each of the three won't use their most damaging attacks until their health is low, and Lupin is pretty tame until he gets somewhat injured, so concentrate on taking them out one at a time.

For the last boss, if you have the GRS Stim Pack from back in the colony and haven't used it yet, use it here! It'll give someone double speed and a huge advantage. You can use it on Jean-Luc to help him on healing duty or on Maelym or LR-388 to give you a huge advantage in offense.

Maelym should be using Plasma Slicer (or Toxic Flechettes if your low on SP or conserving it) on the Princess, and she can also use Vim Vapor to boost damage output.

Jean-Luc should focus mostly on healing with his abilities, and also put him on item duty, restoring SP to anyone who gets low with SciFi Vials. Hopefully you have an Asimov Tank or two to help with that, as well.

There are two strategies for LR-388. Either keep using Fire Bomber, which will eventually toast the Princess's spawned minions (and all three of them are somewhat weak to Incendiary damage, being alien type enemies) or just focus all-out on the Princess with UltraBeam Cannon. She should eventually go down.