"Boundless Traveler" - already better, but still sounds a bit rough...
"Sandro the Digger" was definitely a miss :D He's not a rat-catcher, is he? Unless I'm misunderstanding, and this is about a Necromancer...
"Master of Fear" - also not great, "Lord of Fear" would be better, or at least "Ruler of Fear".
And what does "Light Necromancer" mean? Is it like the topic about "white" chocolate? Maybe "white necromancer" would be better, since you decided to add some lyricism...
"Relentless Trainer" - what is that?)) Maybe "Training Commander" would be better?
"Wealthy Champion" - doesn't sound right.