Assuming responsibility for, commanding, overseeing, managing, directing, leading, running, organizing, supervising, spearheading, controlling, shouldering, heading, dominating, taking the reins, captaining, governing, handling, orchestrating, piloting, dominating, taking the lead, ruling, mastery, holding sway, taking the helm, taking command, taking control, taking the driver's seat, being in charge, being responsible for. These are all excellent synonym choices for taking charge of something or stepping up to take ownership of a situation. Whatever word is your preferred choice, the underlying theme is clear: leading from the front and being accountable for outcomes.