Daredevil, Fearless Fighter

Self-inflicted damage is normally something a deck absorbs and moves past; here it becomes a redirect. The first ability turns any source you control that deals damage to you into an equal-sized bolt at an opponent, and the operative word is damage, not life loss. Painlands that hurt you when tapped, aristocrat pingers that hit your own face, red burn aimed at yourself, and the card's own attack trigger all feed it; effects that merely pay or drain life do nothing, so shocklands (which cost you life, not damage) and fetchlands sit outside the engine entirely. That line between damage and life payment governs how much the redirect is worth: it is only as good as the damage you can reliably deal yourself, and damage is a narrower category than the downside most decks are built to absorb. The attack clause folds engine and hazard into a single trigger. Swinging exiles your top card, deals you damage equal to that card's mana value, and lets you play it that turn, so the exiled damage runs straight into the redirect and forwards that mana value to an opponent regardless of whether you ever cast the card. A high mana value is free burn either way; the "you may play it" clause is upside stacked on top, and because "this turn" leaves the post-combat main open, a cheap flip can be developed normally while its mana value still doubles through the redirect. It asks you to treat your own life total as ammunition rather than a number to guard.