I somehow missed this thread until @Haka-Taka mentioned it in the General Discussion relic thread.
There is a bug with relics that are triggered at the start of the turn. When applying a temporary effect to itself, the relic counts the turn, which makes it useless for most of these relics that only last 1 turn. Two good examples of this happening are Vitality Banner (gold), and Amulet of Haste (silver).
The turn starts and the relic is triggered. The life or speed is increased, but then decreased back to normal as soon as the turn ends. This makes the effect pointless because speed and life are only useful after the turn. On the other hand, this is okay when it happens with Baltasar's Mask because it increases strength during the turn, which is actually useful.
Here is an example of it happening with Amulet of Haste. The first image shows the turn order after the relics are triggered. Thanks to the speed relics, Al Canine gets to take a second turn before the enemy monsters. The second image shows the turn order after Al Canine takes his first turn. He loses his added turn before the enemy monsters (at least one of them).
This actually caused me to lose the attack.
This bug could also affect the Revitalizing Shield fix that @Carlos mentioned above because the description says it starts at the beginning of the turn and lasts for 1 turn. (By the way, in my opinion, Revitalizing Shield would be more useful if it stayed the same, but its description was changed to match it.)