Hello. If you want to add your characters on the same account to your guild, you can either find an active player, invite them to your guild, give them high rank and then get them to add your alts. Or, you can create a second game account. Make a new character, promote them to a higher rank, then use your second account to invite the alts from your main account. You can run 2 instances of the game and alt tab between the two. Thats what I did when I played Iris.
Hope this helps