Promo Set Spoilers 

[VJMP] Grozer the Thunderclap Tyrant, effect revealed

Ness

Works for Fabled, Dark World, or heaven forbid, 4 more years of Burning Abyss.

Jinrai no Boukun Grozer / Grozer the Thunderclap Tyrant
Dark Fiend / Synchro / Effect
LV8 2800/2800
1 Tuner + 1+ non-Tuner Fiend monsters
You can only use this card name’s (1) effect once per turn.
(1) During your opponent’s Main Phase (Quick Effect): You can target 1 Effect Monster on the field; discard 1 monster, and if you do, negate the target’s effect until the end of this turn.
(2) If a Fiend monster is sent from the hand to your GY: You can select 1 of these effects to apply to this card until the end of this turn.
-Cannot be destroyed by battle.
-Cannot be destroyed by an opponent’s card effect.
-Cannot be targeted by an opponent’s card effect.

Source.