First Card of the Rectior Archetype. Anyone who guesses who it references gets a cookie :)

[Phantasm12778]

Constructive Crits Only please.

Cannot be Normal Summoned/Set. Must be Special Summoned by its own effect. You can banish up to 3 "Rectior" cards you control, face-down; Special Summon this card (From your hand). You can only Special Summon "Rectior Peaceslayer" once per turn. If this card is Special Summoned: You can Declare 1 card type (Monster, Spell, or Trap); This card is unaffected by the effects of cards which share the type you declared while it is face-up on the field. Once per turn, you can banish 1 other card you control, then target 1 card on the field; Destroy it. You can only use this effect of "Rectior Peaceslayer" once per turn.

[Phantasm12778]

Any Constructive Crits and or Guesses?

[Rongaulius]

It seems like a less generic Metaltron XII that can't be Tribute Summoned, is only immune to one type of card effect at a time, has to activate its effect to become immune to that type of card effect, and doesn't float into an Extra Deck monster upon destruction. 

Without knowing more about the rest of the archetype, it's impossible to tell how good a boss monster this card is.  If the rest of the archetype is strong and can consistently field this guy, he's decent but not great. Especially the 2950 ATK stat that makes him just a tiny bit weaker than most boss monsters, including his most similar counterpart: Metaltron XII. The fact that his banish/destroy effect isn't a Quick Effect makes him considerably weaker than he might otherwise be. 

[Phantasm12778]

It is not Metaltron. It is actually supposed to be Master Peace, the True Dracoslaying King

[Phantasm12778]

Just with a watered down effect