I've decided to try my luck at The Arena.
And of course, just like my first time in The LG, I got my butt handed to me. LMAO
So I would like to know what is the best setup to use?
My Team are Linked here as you can see.

https://www.sylestia.com/view/pets/?petid=5633146
https://www.sylestia.com/view/pets/?petid=5432716
https://www.sylestia.com/view/pets/?petid=5687573
https://www.sylestia.com/view/pets/?petid=5640570

Any and all help diligently appreciated!!

i set lvl 25 max stat if you want to borrow them for 2-3 weeks

So first, you have to set them a element and a prof point, then you have to train them to level 25 and get legendary gears or mythic ones. I just use a team of two max stats and 1 high stat. (did this cause I over trained my third max XD)
here's a guide to the arena, just focus on when to block and how much mana you should have at all times.
https://www.sylestia.com/forums/?thread=26551
I use a shadow, air and light team, but you can try different combos.
here's my current team:
https://www.sylestia.com/view/pets/?petid=5151340
https://www.sylestia.com/view/pets/?petid=5569630
https://www.sylestia.com/view/pets/?petid=4523617

Thanks Arran

Thanks Storm!

When do I need to give Philter of Unlearning to My Team?
Right at Level 25??

you don't get xp from arena, so you probably won't need philters of unlearning. However, If you use them in the fest zone or something, you should give them philters just to be on the safe side. plus, you can undo it when ever you want to :)

Ok
So the philters of unlearning is to prevent the Pet Level from increasing past a certain point....say in this case going past 25. If so, when I get my Team to lvl 25 it will stop them from going up.

yep. you can use a philter of learning to make them get xp again :) They're usually very cheap, at about 1k each, or you can buy them at the scale shop, at 100 scales each.

Triple shadow is a good setup for arena. There may be others that work, feel free to experiment with it if you like, but it has worked well for me and may be a good place to start.

There's also this guide to the different fights. It is pretty old and some things have been tweaked since then, but the basics are the same, and knowing what the mechanics are before going into a fight can be pretty helpful.