On Defense:

Use your 2 and collect health orbs. At 3 stacks, cast your 3. This should give you a shield with ~10,000 health (before it absorbs incoming fire and gets even stronger) that grants you 90% DR. The remaining 10% of incoming damage will have to overcome your ~80% armor resist before it triggers your [Adaptation], giving you another 90% DR, as you heal the chip damage with more health orbs.

Congratulations, you are passively ignoring 99.8% of all incoming damage! Honestly, I think there's a strong case for dropping Adaptation here and putting in some more power strength- the difference is maybe 1.8% of total damage.

On Offence:
Use 4, use 2, keep your 1 and 3 active. Run up to stuff, hit it with melee until it dies. You win!