well i could recommend you Victoria, she's a good pet for killing off certain monsters but her death quest and getting her will be complicated as well. if you want to go with a lesser complicated quest pet then

Any of these pets would be good for you:

Kanako doesn't mess up too much on builds, she is a str pet. i have her under a water knight but she's quite hard to train as well, getting her isn't too complicated but her death quest is hard

Elin is good at tanking, not too sure about her death quest though. She's a good pet for all elements/types ^^

Hayate is a good STR pet for Earth's I have a Earth that has her rb :). I'm not too sure about her death quest but if you want to obtain her you'll need to have at least more than level 100+ or rbs

Angela doesn't have a rb, she needs a lot of pet lethes cause she tends to build up wis and since you build up wis that could go along with you as well :) if you prefer

Xaolan could be good as well if you don't mind bursting or training her to a certain level. Her death quest isn't really that hard...

I suppose you know more than me already so I didn't have too say any information -- good luck with finding a good pet and I hope this will help you in a way, I think :)

My main has Shasha, she's not too bad but builds up a lot of wis but she's great XD

Wish I could transfer servers and help you but I'm not quite sure about that, I'm from Aries lol