Hmph, let's see...
1) August, he's just a normal and classic mage in manga about mages (ha-ha) outside of few like Zeref, Rufus, Mavis, Jellal, Makarov, Brain, Hades and Irene
2) God Serena, I just like him very bad, one of the greatest introdaction in series from last arc
3) Irene, like August she's great example of ordinary (ha-ha) mage in world of melee fighters calling themselves wizards
4) Neinhart, actually I like him cause he's not as great as other Spriggan, he's weak and just pawn but with great abilities
5/6) Wall, very nice guy, he don't like red lightning just like me
5/6) Bloodman, one man guild from previous arc
And I must add that I really don't like single sided or single element concept of mages, so Ajeel, Invel and Larcade are missed in list but they have nice characters in context
Also Brandish and DiMaria are terrible characters, DiMaria, from start of arc have my love but then ... In Brandish case she's just "turn ally from enemy" character
Jacob is comic refief but he may be on 7th place