You're browsing the GameFAQs Message Boards as a guest. Sign Up for free (or Log In if you already have an account) to be able to post messages, change how messages are displayed, and view media in posts.
Use Toal (Ex version if you have it) and use his yellow skill charged. The enemies spawning in the bottom-left is probably a bug, but it works for you in this case. Makes it incredibly easy to clean most waves up.
Only the sixth stage can be sometimes problematic. Use the boost gauge and burst freely.
It has been a while since I done it, but I think the yellow skill only heals when in boost mode. For the blade-throwing plants, try to hit them as they spawn, run away and do it once more (I think they could only take two times, but it may have been three). It doesn't matter if you get hurt a bit, you should level up soon anyways. The spores, I think I may have killed with burst or with the red skill, but I would have to try it again to be sure.
In general, I activated boost whenever possible (it should fill quickly), used the yellow skill, and if I came across a more difficult wave, I would hit them with a burst first.
Personally, I never completed the Arena on PC (mostly because there was no real incentive, and to get all achievements you had to do boss rush many times). I found the arena reasonably easy on Vita and PS4 compared to the boss rush with some characters.
The knight wave is where I usually die. They are easiest to kill with Hugo and Toal doesn't really have any real good skills for them. Their attacks are somewhat easy to avoid though. It is just easy to let off your skill at the wrong time.
Edit: I usually use a burst when entering the final wave to clear as many of the projectile guys as possible
I got this on the Vita version, I couldn't do it on the PS4 version. Arena 4 nightmare is the hardest of the 6. For the last wave of enemies on arena 6 (the "soldiers" which can do some serious damage and are hard to hit), I used Toal Ex with a lot of patience, a lot of running and long distance attacks (iirc, the wind magic can help here)