Unlocking the glyph
BYSSEPS starts unlocked.
BYSSEPS shines the most in situations where you have to slowly wittle down an enemy, and as such is best used by tanks and regenfighters. Those usually take and deal many hits before bringing down their opponent, thus having plenty of opportunity to apply BYSSEPS due to its cheap mana cost.
Asides from that, it has little utility. A temporary 30% damage boost is nice, but other glyphs and items are often more valuabe in terms of inventory space. The resistance reduction seldom matters; using it on normal enemys will usually cost to much blackspace, and often it's easier to find another way to bypass resistances. However, it can be useful for a berserker facing the Tower of Goo or the monk, since those 2 classes don't synergize that well with BURNDAYRAZ.
The Monk is probably the class who benefits the most from this glyph. Since they have a penalty to their damage, BYSSEPS can help them overcome their low damage. Since they are all about regenfighting and hitting their enemys repeatedly, BYSSEPS is a perfect match for them.
Another class who can make good use of BYSSEPS is the Wizard, especially an Orc Wizard, when played as a hybrid character. Costing only 1 mana, occupying only a small slot and with the option of draining the CPs out of it by converting other items, it costs almost nothing for the Wizard to carry around BYSSEPS and use it whenever possible, compensating somewhat for his otherwise mediocre combat abilities.
Binlor worshippers receive +1 Piety every time they cast BYSSEPS. While not a big deal, it can add up in the long run.