Regen Rate tells what % of a monster's hit points are recovered per second.
Blocked attacks will not damage the monster. Monsters need not carry a shield to block.
Avoided attacks will not damage the monster.
Drain Effectiveness tells what % of a character's mana and life steal apply to that monster. 100 is all, 0 is none.
The chill effectiveness on almost all monsters is -20%, regardless the difficulty.
Resistances over 99% are listed as immunities and monsters will take no damage from that type of attack.
Immunities can be "broken" by skills that lower resistance, if the value drops below 99%. See the Resistances page for more details.
Get to the Infernal Machine as quickly as possibly and kill it before it summons more Elite monsters. Unseelie Dames are particularly deadly due to their curse which significantly slows the player. Mahasattva also can quickly kill the player due to their maximum resistance reduction curse.