With 934 myth, I'd go with upgrading your Hoplite ring to Hero's Ring of Fending and Darklight Plate Belt to Hero's Belt of Fending (both 375 myth). This will give you 4 strength 12 vitality 20 accuracy compared to Warrior's Cuirass which is 4 strength 6 vitality 24 accuracy. If 24 will make you over 475 for turn 1-4 or 484 for turn 5 then go with the chest piece. If not, I believe the ring and belt will serve you better.