Should be...
Lock-On
Continuous Spell
Negate the activation of an effect of an Effect Monster or a Spell or Trap Card that would negate the attack of one of your monsters, and send it to the Graveyard.
And dead-man-walking, that doesn't work either... Skill Drain would still negate it. It cannot be a Continuous Effect, and if it's a Quick Effect it would be negated by Skill Drain. Basically, Skill Drain just trumps it; that's how good Skill Drain is. Also, Divine Wrath (and friends) would still Spell Speed its face if it wasn't a Continuous Effect.
Lock-On
Continuous Spell
Negate the activation of an effect of an Effect Monster or a Spell or Trap Card that would negate the attack of one of your monsters, and send it to the Graveyard.
And dead-man-walking, that doesn't work either... Skill Drain would still negate it. It cannot be a Continuous Effect, and if it's a Quick Effect it would be negated by Skill Drain. Basically, Skill Drain just trumps it; that's how good Skill Drain is. Also, Divine Wrath (and friends) would still Spell Speed its face if it wasn't a Continuous Effect.