What's the best S rank? At the beginning you should probably reroll to get some noob friendly S rank, like Nobunaga Oda or Zhao Yun.
How do i send gifts??? Go to one Harbinger page, then press Evolution.
Why can't i see most of the content in the wiki? It's still a work in progress, more will come in time!
Is this game tier based? Is there a character tier list? No and not at the moment. All Harbingers are strong in a way, but some of them are S rank and rarer because they give strong passives to your Commander. Don't worry, every Harbinger can evolve into an SS rank.
What are the stuff we shud be prioritising our currencies (i.e. SF coins, UL coins) on? You should think well about a teamcomp before spending exp points on Harbingers (we can help you choose in the discord), for the Streetfight Shop i suggest you to get Zhao Yun when you can, he's really strong and a noob friendly unit. For the Urban Legend Shop you should probably chase after Alexander first.
What are Energy Crystals and how to get them? Energy crystal are special universal fragment that you can use for Advancing every character. You obtain them by fusing your spare fragments in the inventory.