Shadowverse

The Mastema comes out onto the battlefield a couple of rounds earlier, but it's just a unit with no real benefit. It's better to place a Zeppelin instead. At least you'll have two units. And the Soul Dominator has no drawbacks; it's an incredibly strong Alucard that doesn't heal at all, but has 2 extra hit points and a chance to gain a huge amount of attack.
I don't have Belphegor, and I won't get him unless he drops randomly. I'm really surprised that they dug up that old Soul Dealer and are pushing it, self-damaging like crazy, ignoring healing... Is the flood of snakes really that incredibly strong? Because I don't see much of it, even less than Runes and Haven, which have become complete garbage, according to the stats.