Medaevum

With all this talk of phenomenal cosmic power, I just want to make sure we're all on the same page with the intended power level of mages and blessed relative to everything else.

An apprentice mage or T1 blessed is able to do the occasional impossible thing - lighting a candle with their mind, for example - but they are not sufficiently strong enough to leverage that power into anything not utterly trivial. Lighting a candle, for example.

A journeyman mage or T2 blessed could reasonably leverage their magical ability into overcoming someone of equal skill to them. If they are in a swordfight with an equally skilled swordsman on even footing, and if the mage/blessed is using their magic to their full potential, the mage/blessed should win.

An adept mage or T3 blessed could leverage their magic into performing competently at tasks which they have no skill, or by supplementing ample skill with ample magic, stand toe to toe against 2-3 lesser skilled adversaries. Someone who is a master at their craft could still outcompete an adept, but only just.

A master mage or T4 blessed is able to hold their own against two or three opponents at once using their magic alone. Even a skilled master in a nonmagical field could not hold a candle to the might of a master's magic. If the master is particularly skilled in something like swordsmanship, they could use their magic to supplement that skill and be able to take out an entire group of unskilled adversaries.

How powerful should a character be relative to some common event monsters?

An angry bear would absolutely trounce an adept or T3 blessed. A master could probably contend with it alone, at a push. 

A minor elemental, only just powerful enough to manifest an avatar, would be at the level of a master mage within the boundaries of its chosen element.

An arrow to the heart is fatal to any mortal, regardless of how powerful they are in theory.