digimon bt20 card list New BT-21 cards for Xros Heart in TCG Deckbuilding for BT20 Examon :

Heliod, God of the Sun was originally printed in Theros

If you use [X Antibody Proto Form], you can digivolve for a low cost

EX3-041 U Digimon Lv.5 Alternative Art Groundramon Color Green Cost 7 DP 7000 Digivolve Cost 1 GreenBlue 4 from Lv.4 Form Ultimate Attribute Virus Type Earth Dragon Card Text 1 [Special Digivolution Condition] [Digivolve]3 from [Coredramon] [Effect] Blocker (When an opponent's Digimon attacks, you may suspend this Digimon to force the opponent to attack it instead.) [Your Turn] [Examon] in your hand can treat this Digimon as level 6 for DNA digivolution

One of the best Jund cards, Korvold applies a ton of pressure, offers endless card draw, pays off other sacrifice outlets, and works with Treasures and fetch lands

But is it possible to guarantee quick success in this case

My suspicion is, after the first time you try him, he won't be enjoyable to play regularly