For pvp everyone and his grandmother will try and dismount you.
After that they kill your pet, and your'e kinda f*cked.
This is why you want ninjutsu.
Mirror images are also very nice (so when u get dismountet, spam thise. they will help deflect melee damage)
If u have a splintering weapon (and yes you really want one of those)
U can use focus attack so you "enhance" the hit XX on your weapon..Fx splint 20 becomes 40.
So this is also a very usefull ninjutsu thing u can use.
for a starter template, try this.
120 weapon (dosent really matter so much)
120 resist (swap this if u want)
080 nox
100 ninjutsu
100 ana
100 tact
100 healing.
(add +20 ninjutsu on juwels to hit 120)
For a more advances setup you can try this (when u feel ready)
swap ana for 100 alchemy