Keep in mind that the aim here is to play everything for 2 mana, so I can safely say that Mournwhelk is strictly better if I'm playing them both for the same cost
As a Modern Jund player myself, Ive cast a lot of them in my time
Monster Effect: Materials: 4 Fiend monsters (1 Fusion, 1 Synchro, 1 Xyz, 1 Pendulum) Must be either Fusion Summoned, or Special Summoned (from your face-down Extra Deck) by banishing the above cards from your field and/or GY
Veidos is certainly the card in the deck with the most potential, thanks to its effect of destroying all monsters on the field provided it's sent from the opponents side of the field to the graveyard
It's very strong in any deck and format looking for mana enablers
Youll be able to double Raviel, Lord of Phantasms ATK to 8000 and crush all your opponents monsters in a single Battle Phase, negate your opponents Spell/Trap effects while you control Hamon, Lord of Striking Thunder in Attack Position, and do a little creative accounting to power up Uria, Lord of Searing Flames far beyond its natural limitations.Complete Domination!Of course, its not enough to just command multiple Sacred Beasts throughout the course of a Duel