Below are some info on pet melding and alternate ways in maxing a pet.

1. Max hp

First step:

level a fierce sheep to lv 94 as host, 
level a potent/fearless ifrit champion to lv 94 as support,

Meld them together will max sheep hp (60 hp).

Second step:

level a new fierce ifrit to lv 92 as host
level the maxed sheep from step 1 to lv 102 as support

Meld them together will max the new ifrit champion (97 hp) (this pet will be around lv 82)

Third step:

Get ready a final host with high hp growth, in this case I will use a whelp.
Get ready your pet with fuse stats affinity/resil/acc etc.

1. meld your ifrit (as support) from 2nd step into a whelp (as host) (any stats/affinity/attitude) and max the hp of this whelp.

2. Pet with fuse stats affinity/resil/acc etc as host, Maxed hp whelp as support, together with charm of addition, 1 meld will max your final fuse + mutated.

This method you will only need 1 charm, which is charm of addition, no need 10 melds etc can save you lots of time/exp/gold. Level require to meld each step is only an estimate, please use the preview in forge for successful maxing!

Max int/str:

First step:

In this guide I will max a pyra sensible pet.

1. Catch a pyra "clever Dewdrop bunny" and level it to 90 as host (This mob is at Dirtpool cave {881,841} next to Ancestral Ruins, depends on what pet you are maxing you will use different affinity, bright bunny.)
Note: Clever bunny = bright

2. Prepare a pyra, (passionate/pious), ifrit champion, level 90 as support.

3. Meld together you will have a lv 78, pyra, (bright/passionate/pious), dewdrop bunny, with str/int around 4/5.

4. If the attitude stays bright, you will have to meld it again with any pets to change it to pious or passionate for more transfer of int/str later.

Second step:

1. Prepare a pyra, bright, lava golem (in judium), level 90 as host
2. Get ready the pyra, (passionate/pious), level 90 dewdrop bunny from 1st step as support.

3. Meld together you will have a pyra, (passionate/pious), level 78, lava golem with str/int around 6/7

Third step:

1. prepare a pyra, bright, fallen one (in ole), level 90 as host
2. Get ready the pyra lava golem from 2nd step, (passionate/pious), level 94

3. meld together you will have a pyra, (bright/passionate/pious), lv 79, fallen one with str/int around 9/9.8

Last step:

1. level the fallen one from 3rd step to 90+ or 100+, depends on the final pet you wanted to max (i.e. if you want to max white dragon, you will probably want to level it to lv 100+, again, check preview in forge)

2. meld your fallen one (support) onto the final pet (e.g. white dragon lv 90+ pyra sensible, Host)

Pet melding chance:

Pet meld number on host // Success // Success after using the orange charm

0 // 100% // 100%

1 // 87.50% // 100%

2 // 75.00% // 100% 

3 // 62.50% // 92.50%

4 // 50.00% // 80.00%

5 // 37.50% // 67.50%

6 // 25.00% // 55.00%

7 // 25.00% // 55.00% 

8 // 25.00% // 55.00% 

9 // 25.00% // 55.00% 

Pet Rank:

Lots of factors contribute to the final pet rank, this is espcially important when you are trying to pick a host for mutation. Not only it looks good to have 600 rank, but also some pet skills uses pet rank as one of the damage calculation component.

Below is a break down of how the ranking works.

Factors that affect the pet rank: Pet affinity, Pet fusion stats, pet stats growth (hp/str/int/def/resist)

Regarding to pet affinity, oora and pyra contribute to rank the most, where unda is in the middle, widu and edra gives the lowest.

Pet fusion stats:

Pet fuse stats includes (oora affinity) contribute 14 rank to final 

Pet fuse stats includes (pyra affinity) contribute 14 rank to final 

Pet fuse stats includes (widu affinity) contribute 4 rank to final 

Pet fuse stats includes (edra affinity) contribute 2 rank to final 

Pet fuse stats includes (unda affinity) contribute 6 rank to final 

Pet fuse stats includes (hp % ) contribute 13 rank to final 

Pet fuse stats includes (mp % ) contribute 13 rank to final

Pet fuse stats includes (resist %) contribute 13 rank to final 

Pet fuse stats includes (int) contribute 19 rank to final 

Pet fuse stats includes (resil) contribute 14 rank to final 

Pet fuse stats includes (acc) contribute 14 rank to final 

Pet fuse stats includes (str) contribute 22 rank to final 

Pet fuse stats includes (hp regen) contribute 4 rank to final 

In pet growth stats, resist + def, every 0.1 is 3 pet rank (e.g. a mechen pet that have 1.1 def, resist 0.7, total is 1.8 and a elementa pet that have def 0.7, resist 0.8, total 1.5, This mechen pet will have 9 more rank than the elementa pet.)

When we are deciding on a host pet, it is important to pick a pet with a lot of fuse stats, as well as high def and resist. This is why white dragon is relatively easier to get rank 600 (max) than other pet such as tomero gunner because of the high def/resist it comes with naturally.

Pet affinity growth:

With some pet skills, pet affinity also contribute to damage.

Scalen pets all rounded affinity growth is the highest, follow by elementa, and humaniod.

Other pets that have a slightly superior affinity growth: Aerax, high pyra affinity // Mechen, high oora affinity // Haunten, high edra affinity 

If you want to make a potent oora pet, it would be best to use a mechen type pet as host (such as AR, or the fat rolling ball in amaz which i forgot name XD), to make a pyra sensible it would be best to use devline champion as host, fearless edra would use haunten. Scalen and elementa is suitable to all as host.
Unda pious use chaos efreet or lava golem also ok!

Credits go to bubblieeee.