Mechanically, the lord of the dead scales in power based on the presence of other villain characters in play
Gyarados ex A powerhouse Pokemon with bulk in spades, Gyarados ex has 180 HP and one attack: Rampaging Whirlpool
Your Temple Is Under Attack is a board protection spell, sure, but should also be used politically to sweeten a bargain
For example, Roost of Drakes will always have a mana value of 1, even when cast for 4 mana with its kicker, Voidpouncer will always have a mana value of 2, and Murasa Sproutling will always have a mana value of 3, etc
Second effect reflects his physical Electric attacks (like Spark/Thunder Fang)
You can get to +1 either by trading off Fenrir or successfully tying in power with Chapter III