I love making heroes. The problem is, there are two major considerations for any hero; the Theme and the Role. You've given us the barest Theme, and not very much to go on for the role. So tell us:
Theme
- What faction/race are they aligned with?
- What's the story behind this character? (Far Seer = head shaman, in touch with elements and seeing ahead to the Horde's future)
- Where did they come from/Under what circumstances are they created? (i.e. Paladin = holy warrior; Death Knight = corrupted Paladin)
- What do they look like? (Keeper of the Grove = 4-legged "good centaur", super-druid with tree-claw arm & flowing leafy tresses.)
Role
- This is warcraft after all: What part of the battle will they be in? front lines? off to the side? ranged support? back-in-the-back (caster/ranged)?
- What will they be doing outside of combat?
- What are some parameters on how they will play (slowly build up strength to dominate; quick overpowering force; long-term leaching; AoE vs single-target focused; etc)
- etc
Until you answer those kinds of things (for yourself & us), we can't really help you. Good luck!