Multiple Pet Build Guide

Why Pet?
Personally myself, I would treat pet as one of later game content. As pet provide much unique skill set of their own, allow you to easily transfer this skill set to any character as you want.
Some highlight skills that player often interest in pet: Ragging Blow/Magic Lance for extra damage, Encourage/Clear Mind for player stats buff , Cover for reducing damage, Rage Attack for a decoy aggro, Shield Break for high defensive boss,... many more if you can put up your will to invest.
The real advantage is that not all of these skills are available to all characters and even if that character has it, casting them by yourself could significantly reduce your performance in battle. Take pet, it's hardship to get a proper one, but the reward is a significant advantage.

How to start?
There should be a decent amount of pet guide out there. I just put a few good links right here so you can easily navigate them (and strongly suggest you to read this guide to understand how pet system works):
Guide: http://mytoram.blogspot.com/p/pet-guide.html
Pet fusion optimizer: http://coryn.club/pet_fusion_optimizer.php
Pet leveling: http://coryn.club/pet_leveling.php

In this guide, I will show one straight forward way of build pet, but of course you should branch out the different build for your pet in which I will mention at the bottom of this guide.

There is a few core requirement that you need before investing in pet:

• A dedicate character for taming skills. Includes: [Taming] lv.10, [Capture Technique] minimum lv.5, [Skillful Capture] lv.10 and [Careful Capture] lv.10 for capturing; [Pet Mp Charge] lv.10 optional for pet active skill leveling; [Quick Motion] lv.10 for pet passive skill leveling. Minimum 35 SP.
• A decent number of pet slot so you can leveling multiple of pets. Increase your hibernate pet slots as well.
• Good number of DPS characters if you want pet get to higher level (>100). Interruption skills also recommend for extra boss xp.​

The build
Pet builds are redirected to this post:
https://toramonline.com/index.php?threads/multiple-pet-build-guide.51133/#post-525280

Farming pet
So there is the build, but how are you suppose to satisfy these requirements?

The first key is to keep capture them until you get the skills and properties:
For example of the Tank pet: try capture as many pets as you can with their max level around 160. Finding one with devoted only with their nature. And at least one of these has type of Phy Def./Mag. Def. (Finding only type Phy Def./Mag. Def. then one of them with nature Devoted also works). Release them at your land, then first thing is try to get the Skill requirement of either [First parent skill] or [Second parent skill] so you can assign these two as last two pets. If one obtain the [First parent skill], this will be the 3rd pet, if one obtain the [Second parent skill], this will be the 4th pet. Other pet that fail to obtain the skills can be kicked of your land (oof) or be 1st/2nd pet. The [Main pet skill] is only come after all fusion finished and the skill always need to be guaranteed.

Second key is fusion pet and keep leveling them up:
Fusion between two pets will take the average level of the two (the current level of two pets, not max level) plus with 1. Example of Tank pet again: 1st pet at lvl 60 + 2nd pet at lvl 116 (+ 1) = Fused pet X at level 1 (max level 89)
Fused pet X at lvl 89 + 3rd pet at lvl 145 (+ 1) = Fused pet Y at level 1 (max level 118)
Fused pet Y at lvl 118 + 4th at lvl 160 (+ 1) = Main pet at level 1 (max level 140)
After each fusion you will need level them up and assign their stats as frequently as possible
Hint: You can rename your pet to something like: "1st.lvl60" so you can remember later on this pet is the first with lvl 60 as target

Third key is training pet:
You need to train the pet first before leveling and ideally you need correct type of feed buff to maximize your pet stats. Feed pet with either 1k spina/3k spina food can achieve 30% or 50% discipline bonus. 30% is required to guarantee every easy training is success. 50% is required for hard training. Go with main stat you need first, e.g.: VIT for support/tank pet, stat of pet weapon for DPS.
For leveling pet skill, you will need to go against a decent HP boss but weak attack if possible. Don't kill the boss, just let your pet doing attack of active skill to raise skill level (passive skill also slowly raise up after each normal attack). If you want to speed up active skill leveling of pet, you'll need character with [Pet MP Charge].

Branching out
These builds are obviously not the most effective way to get your pet done. There are several other methods you can try out with pet build to fully customize your need.
Changing number of pet generation?

Spoiler

Higher number of generation will increase maximum power pet can achieve (more ideal for DPS pet). It is also however a lot more painful to leveling them up. So if it is required more generation, try to keep those generation at lower level if possible. E.g: 1st pet lvl 60, 2nd pet lvl 60, 3rd pet lvl 60, ... 20th pet lvl 120.
Less number of generation will cause the pet suffer to get AMPR (due to AMPR nerf for having more pet in party). Generation with 4 pets in this case is very ideal for balancing leveling and pet effectiveness issue.

Faster leveling for pet?

Spoiler

Check the link on top of this guide for Pet fusion optimizer.
First think what level of your main pet might be. Hint: after every 20 pet level, the leveling become progressively more difficult. Harder boss and slower leveling. Try to stick to a number divisible by 20. E.g. 80,100,120,140,...
Now test with level of 1st pet which is often at lower level. E.g: Target level of 120 can try with Original level of 40, 60, 80. Compare the different of xp required for yourself.
Note: 2 steps requires from optimizer calculator is equivalent to 4 generation pet.

Which pet skills/properties should you go for?

Spoiler

You should refer back to the guide I link on top again. Focus on nature section and skills of the pet first, then its weapon and element if you want pet do damage or type if you want to focus on pet stats. Ideally you can start with a supportive type pet so you can slowly get use to building a pet.
If pet needs using high MP skills or spamming skills: get more MP from [nature: Justice] [skill: Absorb MP]
If pet needs lots of defense: get HP and defense bonus from [nature: Devoted, Calm] [skill: HP gain]
And many many more...
This is just a rough list you can try to get a build out: Healing pet, Shield break pet, Tank pet, Defense boost pet, AoE pet, Stat boost pet,...

Fusing main pet again?

Spoiler

To fuse your main pet again, you need to sacrifice one of parent skills for current pet. If current main pet keeps [First parent skill], then the one to be fused with also need [Second parent skill] at level 10. After fusion, you also need to get [Main pet skill] again. This is also required if your main pet requires 3 non guarantee skills, in which you must gamble for third skill and if it fail, keep one of parent skills and fuse to get a new main pet.

 

The build
These are 4 generation pet build, also means raising 4 pets and fused them in order to become 1 main pet at the end.

This is an example of ATK/MATK buff pet. This is relatively an easy pet to build and doesn't need to be high level to become useful.

Spoiler

Main pet is expected to have:

Pet skills: [First parent skill: Absorb MP] [Second parent skill: Encourage/Clear Mind] [Main pet skill: Encourage/Clear Mind]
Pet properties: [weapon: any] [type: any] [nature: Justice]
Pet level: 80​

Four generation of pet are:

1st pet: Skill: any | Weapon: any | Type: any| Nature: Justice | Level: 60 - Raise pet VIT (HP/DEF) first then DEX (accuracy)
2nd pet: Skill: any | Weapon: any | Type: any | Nature: any | Level: 60 - Raise pet VIT first then DEX
3rd pet: Skill: Absorb MP | Weapon: any | Type: any | Nature: any | Level: 60 - Raise pet VIT first then DEX. Raise its [Absorb MP] skill to minimum lvl 5
4th pet: Skill: Encourage or Clear Mind | Weapon: any | Type: any | Nature: any | Level: 97 - Raise pet VIT first then DEX. Raise its [Encourage/Clear Mind] skill to lvl 10
Main Pet: Skill: any | Weapon: any | Type: any | Nature: any | Level: 80 - Raise pet VIT first then DEX.​

This is an example build for a Shield Break pet. Since this skill requires high MP cost and need to cast skill often to become useful, it will need other pet skills/properties that can support pet MP recovery.

Spoiler

Main pet is expected to have:

Pet skills: [First parent skill: Absorb MP] [Second parent skill: Shield break] [Main pet skill: any]
Pet properties: [weapon: any] [type: Accurate] [nature: Justice]
Pet level: 120​

Four generation of pet are:

1st pet: Skill: any | Weapon: any | Type: Accurate | Nature: Justice | Level: 80 - Raise pet VIT (HP/DEF) first then DEX (accuracy)
2nd pet: Skill: any | Weapon: any | Type: any | Nature: Justice | Level: 84 - Raise pet VIT first then DEX
3rd pet: Skill: Absorb MP | Weapon: any | Type: any | Nature: Justice | Level: 111 - Raise pet VIT first then DEX. Raise its [Absorb MP] skill to lvl 10
4th pet: Skill: Shield Break | Weapon: any | Type: any | Nature: Justice | Level: 140 - Raise pet VIT first then DEX. Raise its [Shield Break] skill to lvl 10
Main Pet: Skill: any | Weapon: any | Type: any | Nature: Justice | Level: 120 - Raise pet VIT first then DEX and INT(maxMP)​

This is another example build for a Tank pet. Pet requires high aggro and also take damage away from the player.

Spoiler

Main pet is expected to have:

Pet skills: [First parent skill: HP Gain] [Second parent skill: Cover] [Main pet skill: Rage Attack]
Pet properties: [weapon: any] [type: Phy. Def./Mag. Def.] [nature: Devoted]
Pet level: 140​

Four generation of pet are:

1st pet: Skill: any | Weapon: any | Type: Phy. Def./Mag. Def. | Nature: Devoted | Level: 60 - Raise pet VIT(HP/DEF) first then INT(MDEF)
2nd pet: Skill: any | Weapon: any | Type: any | Nature: Devoted | Level: 116 - Raise pet VIT first then INT
3rd pet: Skill: HP Gain | Weapon: any | Type: any | Nature: Devoted | Level: 145 - Raise pet VIT first then INT. Raise its [HP Gain] skill to lvl 10
4th pet: Skill: Cover | Weapon: any | Type: any | Nature: Devoted | Level: 160 - Raise pet VIT first then INT. Raise its [Cover] skill to lvl 5-10
Main Pet: Skill: Rage Attack | Weapon: any | Type: any | Nature: Devoted | Level: 140 - Raise pet VIT first then INT. Raise its [Rage Attack] skill to lvl 10​