jerseyteufel
My life stinks! What's your excuse?

Equipment is way more important then levels in Final Fantasy XII. Characters gain little stat gains, if any, each level up. The HP & MP increases but stats may just get 1 point.

One more thing concerning Thundara for the Mateus fight, if you have the Storm Staff that will immensely help; that staff boosts lightning damage by 50%.

Also, if you try to do the Adrammelech fight, he is weak to ice so with Blizzara and the Glacial Staff which enhances ice damage by 50% that will be a great aid. There are a bunch of undead enemies that spawn during that fight so Curaga or Cura will help; do not use Phoenix Downs or Raise because those heal undead. Potions also work. Once again Gil Toss and Horology - with the a high second minute for the latter - are also useful.

Do you have Thundara? That spell is very useful for fighting against Mateus and the minions that show up during the fight. If you have a lot of gil to spare, "Gil Toss" technick is very good. If the second-minute number on the game clock (example: 23:38:10, the 8 is the second-minute number) is 7 - 9 horology is another great technick to use. How damage is calculated for Horology is through the user's level and the second-minute number on the game clock along with some other numbers. The higher the level and second-minute the more damage. An aspect that makes Gil Toss and Horology pretty good are that they are area of affect technicks which would allow you to attack Mateus and the minions simultaneously.

I recently just passed that point during my second play-through; for the Mateus fight I used Adrammelech - the thunder Esper - which can be obtained in the Zertinan Caverns via Ozmone Plains. It can be a round about way to beat Mateus since the Adrammelech fight is probably harder, but Adrammelech is a beast against Mateus fight with the correct buffs: Reflect, Bubble, Protect, & Haste. With Reflect, your character will need an Opal Ring (allows magicks to pass through Reflect) which can be stolen from the bomb-type enemy in Zertinan Caverns. They are a rare steal so it's best to have the Thief's Cuffs accessory equipped on the character stealing.

Finally, it appears you are unfamiliar with how Visitor Messages work. I didn't know you had responded to me because you posted a Visitor Message on your own page. The next time you want to leave a Visitor Message (VM) to anybody just go to their profile page and type in the Message box. For me you could just click on "View Conversation" which shows our whole conversation and it allows you to leave a reply.

Im at the one for Mateus there. I am not sure if I am strong enough to combat that. All of my characters are at lvl 31 with lvl 3 mist ability

Which boss fight are you stuck on in the Stillshrine of Miriam (Final Fantasy XII)?