This mobile game is available in some countries at the moment (I read it's Japan and Europe) and I'm currently playing the version from Japan iOS app store and it's entirely in English so there are no language issues. After coming from the 3DS version of Fire Emblem, I'm a little not used to the sprites not being pixelated. If you get any retry prompts, just retry instead of returning to title screen.
Tier list links
https://fireemblem.gamepress.gg/tier-list
http://altema.jp/fe-heroes/risemara
https://fireemblem.gamewith.jp/article/show/38845
https://fireemblem.gamewith.jp/article/show/38279#new (Beginner roll tier list)
https://game8.jp/fe-fireemblem/useful/117832
http://feheroes.wiki/Tier_List (Based on Altema's list above but in an easy to read format, in English plus with details of the cards)
The first link also had some other guides worth checking out so do navigate around and check it out! The rest of the links above are in Japanese but there are plenty of pictures so it should not be too hard to understand. As the game is still so new, you'll probably want to check back to those sites once in a while as there will most likely be updates.
It seems like Takumi is one of the best card at the moment, I think mainly due to the skill that allows him to counterattack from any distance and being a neutral class. Takumi should be the safest option to reroll for now unless you have some other favourite character in mind.
Rerolling tips and links
https://www.reddit.com/r/FireEmblemHeroes/comments/5rlibt/rerolling_tips/
https://www.reddit.com/r/FireEmblemHeroes/comments/5rmpn5/thinking_of_rerolling_heres_how_fast_you_get_20/
https://www.reddit.com/r/FireEmblemHeroes/comments/5rm4wm/tip_for_rerollers_turn_off_the_battle_animations/
Basically, try to save up 20 orbs so when you "roll" the hatcher, you can "roll" continuously and get 5 rolls instead of 4 if you stay on the board of 5 stones shown due to the discount.
On iOS, I have to delete the app and re-download and so far it is more tedious than Puzzle & Dragons due to the bigger download required. I'm trying to reroll a while to see if I can get at least a 5*. Refer to the tier list above on what are the better cards.
You can tap the animation to cancel it immediately in the initial tutorial battles. In the subsequent rounds after the 300+mb download, turning on auto-battle should be faster than trying to make the moves yourself.
Other Useful links
https://www.reddit.com/r/FireEmblemHeroes/ as usual.
I got some of the tier lists sites from there while GameWith is the usual place I check for Puzzle & Dragons.
http://nintendoeverything.com/my-nintendo-rewards-for-fire-emblem-heroes/
When you settled down on an account, you can link it to My Nintendo to get 10 orbs. The page also includes a list of rewards you can claim from My Nintendo for the game.
https://serenesforest.net/fire-emblem-heroes/heroes/availability-and-rates/
Interesting tip on the increase in rate for 5* after every 5 failed attempt.
https://www.reddit.com/r/FireEmblemHeroes/comments/5rtakd/starting_guide_and_tips_to_get_started/
Don't forget to learn and equip your character's skills. I think it is good to learn all the different skills first instead of trying to all-in those with multiple levels. Most of the skills are passives or utilities so being able to equip more will be more beneficial IMO.
Once you have a decent team, consider investing your orbs to upgrade your castle as it boosts exp.
*Last Update*
I haven't been playing this game at all as I didn't have time for it. It turns out that there are more strategy involved in team building for arena than I thought after I checked out this thread at gamefaqs: https://www.gamefaqs.com/boards/204447-fire-emblem-heroes/74974943. The link to the "30-page arena guide": https://drive.google.com/file/d/0B_qKZoT3ggeZSFEwMXFxYlRWVVk/view. I think it might be outdated since it has been a few months but nevertheless, I think it might be a good reference. I won't be updating this post anymore. Good luck, have fun!
