Arix haunts his way into Teleria as the Login Reward Champion you will obtain after Lady Eresh. This means unless you pull the champion from an Ancient Shard (you cannot pull Arix from Sacreds), you will need to play for just over 2 years before you will collect Arix.
As a HP based champion, Arix will likely deal decent but not supreme damage. Both the A1 and A2 will attack all enemies making this champion an ideal Stun Set or Taunting set champion especially with the A2 carrying its own Stun (although not 100% to land). In addition, Arix will place an Ally Protection on all allies except himself and place a Counter-Attack buff on himself.
You can play Arix as a protector for your team utilising the control and self sustain healing in his passive. I recommend taking Harvest Despair mastery if you do this to enable Leech for non-boss content that can help your team heal. You could also setup Arix in Arena Defense to be annoying if you can enable the Counter-Attack and try to remove buffs on the A1.
Overall a decent champion although you may find little to no use by the time you do eventually earn this champion from your daily logins!
This guide will be updated once we have had an opportunity to play test.