Complex sentence: When he activates his powers Josiah transforms into a monstrous, grey, stone-like seven foot giant and an energy corona begins to spark about his body, he gains great strength, invulnerability and possibly other energy based powers.
Split into simpler sentences: When he activates his powers Josiah transforms into a monstrous, grey, stone-like seven foot giant, and an energy corona begins to spark about his body. He gains great strength, invulnerability and possibly other energy based powers.