I recommend playing around with high level (+9ish) Ring of Arcana for interesting builds. A few examples (I mostly play Huntress):

Arcana + Projecting Huntress + Talisman of Foresight/lots of PoMindVision: snipe every enemy from across walls. Easy win.

Arcana + Warden + Blooming spirit bow: unlimited grass, every shot surrounds the target with grass breaking their line of sight, super easy farming.

Arcana + Warlock (or Vampiric) + Kinetic: 1hit KO plus full heal melee strikes.

Arcana + Mage w/Shield Battery + Potential: your staff/wands recharge very quickly, enabling constant use of Shield Battery.

Did you know that mobs on fire take bonus damage from additional blazing hits? Arcana + Blazing + RoFuror: char them to death before the turn clock fills, try with Gladiator.

You can also use the RoArcana as the "ring of other rings". At high level, it makes Lucky = high level RoWealth, Swiftness = RoHaste, Anti-magic becomes something like RoElements, Stone become something like RoTenacity. Arcana + Lucky + Swiftness: like having a RoHaste + RoWealth and you still have an open slot for another ring/artifact.