1995 seaking pokemon card - 119/165 - Pokemon 151 - Reverse Foil [W] Horn Attack (10) [1W] Waterfall (30) Seaking - Base Set 2

1 Pathrazer of Ulamog

Black Star Promo cards are as legal to play as any other Pokmon TCG card, so long as they have an appropriate regulation mark

Their only ability lets you exile a card from your graveyard to discover for X, with X equalling the mana value of that card

It needs more 2-drop creatures and/or removal for early defense, but once it gets to four mana, Zendikar Incarnates are going to start taking over the game

Counterspell and Mana Drain would require at least 30 blue sources which is utopian in a deck that also wants to cast Land Tax turn one

There are also a couple additional planeswalkers that can more or less win the game if left unchecked in the form of Tevesh Szat, Doom of Fools and Chandra, Awakened Inferno