Complex sentence: Sanders is a welcoming but firm presence, further undermining Hindle at regular opportunities, and it is therefore somewhat unnerving when Sanders decides to venture out into the jungle in the TSS, leaving the highly strung Hindle in charge.
Split into simpler sentences: Sanders is a welcoming but gruff presence, further undermining Hindle at regular intervals. At this point Sanders decides to venture out into the jungle in the TSS, leaving the highly strung Hindle in charge.