Let's get started!

So, the first thing on this page is about how to invest properly on the first few heroes in the game.

Galahad- He is a okay hero, a big damage dealer, a tank, but he can be replaced soon.

Artemis- Seems better than Galahad in early campaign, but becomes not as good later.

Thea- Seems like she is a horrible healer to start, but she gets good when you put a lot of investing in her.

Ginger- A big damage dealer, but horrible in late campaign because she can be replaced or interrupted more.

Astaroth- One of the best tanks in the game, especially at violet rank with his ability Last Words. It causes him to resurrect with a specific amount of health.

Phobos- I think he is very good. His ultimate ability, Paralysis, stuns an enemy for around 6 seconds, while slowly dealing damage. At violet, his ability Bound by Fear, steals energy from the stunned enemy as well.

Aurora- Aurora is a great tank because she can do a lot of magic damage instead of just physical damage.

Keira- Keira is a big damage dealer and one of the best damage dealers in the game. She is a marksman and she can deal damage in the back row starting at blue rank, with her ability, Dancing Blades. It turns her basic attack into blades that bounce of the team to the back. Chances are different though. Her violet ability, Piercing Pain, can make her basic attack do extra damage if she penetrates enough armor.

Fox- Fox is like Ginger; good in early, not so good in late. Plus, Fox doesn't deal that much damage. Her abilities do some damage, but mainly focus on helping her ultimate skill.

Finally, the last hero in the first three chapters, Mojo. You can get his soul stones from the boss battles in chapter 1 and 3, but he is not that good. He doesn't deal that much damage, but the best part about him is that he deals some magic damage and he can also heal a little bit. His ultimate skill can easily be interrupted by stunning him though.