Oh, I jest, of course. Use whichever is appropriate each time. Which doesn't necessarily mean always Verholy when white lower or always Verflare when black lower: if you had a stone/fire proc ready of the lesser side, it's usually better to do the finisher corresponding to the higher one, for the 20% chance of a proc, thus having a proc on both sides after the melee combo finisher. If the mana was very uneven it is not recommended, since you can instantly unbalance it, but when they're 10 or less apart, it works.