Whenever Combustion Man attacks, destroy target permanent unless its controller has Combustion Man deal damage to them equal to his power.
Suit upCombustion Man as a punisher-Voltron threat: every attack forces an opponent to either lose a key permanent or eat damage equal to his power, so you swing in repeatedly to grind boards while pressuring life totals. Pump his power and grant evasion/extra combats to make the 'damage' option lethal and the 'destroy' option backbreaking. You win by either dismantling the table's mana and blockers or by funneling huge unblocked hits into one player.
Built-in repeatable removal that hits any permanent type, including lands, planeswalkers, and artifacts
Lose-lose for opponents: they sacrifice value or take potentially lethal damage
Scales hard with power buffs and extra-combat effects in mono-red
Mono-color consistency makes mana and color fixing trivial
Effect only triggers on attack, so he must survive and connect each turn
High commander tax and removal-magnet status make recasting costly
Mono-red lacks card advantage and struggles against heavy lifegain and fogs
Opponents can simply choose to take the damage when their boards matter more