Hiya @Gavi,
first some general advice:
Who to work on?
In terms of your question on who to focus on, I would suggest that you level one hero of each colour. Feed them only heroes of the same colour. This way you get an extra 20% boost in experience (making it more efficient in the long run).
Red
- Gormek to 3-60
- Namahage to max (3-50)
- Jahangir to max (3-50)
- Sumitomo to 3-60
- Ascend first 4* Red to final ascension.
I would ascend Kelile first then Gormek personally. While the defence down is great, I think that Gormek is the worst of the three ramming pulverizers (Grimm > Tiburtus > Gormek).
Blue
- Kiril to 3-60
- Gato to 3-50
- Valen to 3-50
- Kiril to 4-70
- Grimm to 4-70
While grimm is an amazing attacker, I will suggest Kiril first in terms of ascending. Purely because you have no other 4* healer at this point… Kiril is a great healer & has the benefit of the attack & defence buff too!
Green
- Mnesseus to 3-50
- Friar Tuck to 3-50
Unfortunately you seem to be lacking any other greens to work on after that… if you don’t get any new ones, start off-colour feeding to another project you’re working on.
Yellow
- Wu Kong to 3-60
- Hu Tao to 3-60
- Melia to 3-50
- Danzaburo to 3-50
- Wu Kong to 4-70
- Hu Tao to 4-70
- Danza to 4-70
- Leonidas to 3-70
As @CaptBooboo said, wu kong is a titan killer! basically he massively buffs your tile damage & allows you to do much more damage to titans. more damage = higher loot tier = better chance at materials = able to ascend more heroes.
Purple
- Tiburtus to 3-60
- Gill-Ra to 3-50
- Cyprian to 3-60
- Proteus to 4-70
- Tiburtus to 4-70
- Cyprian to 4-70
Proteus & Tiburtus are great 4* heroes. Proteus will massively help in completing map stages & challenge events.
Getting more Heroes
To get more heroes I would focus on running Training Camp level 13 continuously. This will pump out a pretty steady stream of 3* & occasional 4* heroes.
Use Training Camp Level 11 to keep making feeders to level your heroes up on the remaining camps
Keep going with base building (can even run a second TC13 if you want) until you get to Stronghold level 20. At this stage, build your fourth camp all the way up to TC20.
At this point, stop using TC13 & start using TC20. It runs the same time (2 days) but gives a better stream of 4* heroes with the odd chance of getting a 5* hero.
When you get to TC20, I would run the 2 of the other camps at TC11 to keep making feeders. the fourth camp you can level up to TC20 and run 2 simultaneously to double your chances of getting more heroes.