Should i just keep developing the Legendaries and upgrade them as i can?
A: Keep developing your 5 best most often.
Which are the ones i should keep?
A: For right now, Keep all of them. You will need 5 for the bases and 3 for each tower garrison. e.g. if you have 4 advanced towers and five bases you will use 17 heros.
Which ones should i consume and by who? What does consuming do? I don't really get it, apart from it adds to the numbers!
A: You consume the slimes, that is what they are there for.
A: Consuming will increase the hero's skill level. Each skill is different and gives different benefits. The higher the skill level, the more effective it is.
Am i right to presume the more shards they cost, the better they are?
A: Yes and No. Legends are better than Elite, which are better than Ordinary. Within each group, each hero is different. It all depends on what you want them to do. e.g. I think the Legend Druid makes the biggest difference to an army, especially when his skill level gets higher.
When consumed, does the upgrading count as better, ie. Is it worth more to consume a L20 hero than a L1 or does it not matter? Is it better to consume a slime or a hero?
A: In general, yes. But it is a little bit more complicated than that. Don't think of it as levels 2, 6 or 18. Think of them as 1, 2, 4 7 star heroes.
A: Consume the slimes, that is what they are there for. In general,
Does every body just pick their top 5 and run with them as much as you can, developing and upgrading them or is it better to have a lot more?
I like the advice of choosing 5 main heroes to advance. Your might increases with each hero, their levels, and star ranking. But might is a punishment, forcing you to raid & defend against tougher opponents. Keeping some around for garrisons is probably a fine idea if you favor defense. Target levels for garrison heroes are 50, 75 (x 2), and ??.
Of course some heroes are good for raiding, and some are good for arena. The Druid and Spirit Mage are good for both. I wish I had a Spirit Mage! Of the ones you have, you have to decide if you want a stronger raiding team or arena team. I wasn't sure so I went for a mix. Not taking into account your talents, I'd say:
Paladin: Kinda weak in arena, pretty good tank for raiding I think. Ability is not all that useful. I'm not sure, maybe use him.
Champion: Fairly good in both. Use him.
Succubus: Very strong in arena, and ranged attack makes her good for raiding even though her ability is useless there. Use her.
Executioner: Decent in arena, a bit weak when raiding.
Cyclops: Mediocre in both. When raiding, I find his AoE attack is mis-aimed and short-ranged. I recently
Werewolf: Not too useful.
Serpent Queen: Pretty good raiding, large area of effect + ranged attack. Just okay in arena. I'd use her.
Pain-Da: Attack is too slow to help in arena. Ability is good for raiding.
Ice Demon: no.
Assassin: Bad in raids (dies *fast*), best elite in arena unless perhaps you want to attack in a unified clump.
So for your 5th I'd say either assassin (arena), executioner (compromise), or pain-da (raid).
Of your green heroes, the Angel is worth considering. Heal is much too slow to help in the arena, but for raiding I think it's nice to have some healing.
KEEP ALL OF YOUR LEGENDS!!!!
As they get higher, they will be critical in certain situations.
They are specialized.
I rotate through my 7 legends for different scenarios.
(Yes, the Spirit Mage is used in all scenarios.)
Thanks for putting on the needed info in the post to answer the questions you have asked. You are going to want to level your legendary heroes and use HB on them and them alone. Dont level other heroes, and you could consume them depeding on your might. If you might is too high, getting rid of unused heroes is the best way to drop it by a significant amount.
Every gem you get you should use for hero rolls. After rolling for all legends in the game, roll for talents. There's no need to use gems to power level building etc. I did that on my main account and while my base is big and shiny it wasn't needed. I do have really good talent though, and that's why I never need Honor Badges (HB) since the talents make staying in the top 100 in the arena easy.
I'm not trying to promote my channel, but I do answer most of these quetions with my videos. I'm on page 2 of the might rankings and my channel is spelled on my base if you want to see it.