Gloom itself takes up, what, ten percent of the card space
For better or worse, Partner is a part of the format now, and barring a Companion-esque power-level errata coming sometime in the future (extremely unlikely, given that Partner has no real effect on Constructed formats, which is what drove the Companion errata), it will remain difficult to balance and a point of contention
Split Up is a three-mana mass removal spell that will no doubt create headaches in Standard - it's excellent at removing blockers after an alpha-strike from an army of tokens , for instance, but it's also a great early answer to a deck curving out into threats on turns one through three
If condition isnt a dealbreaker for you, then this set would make an excellent addition to your collection
Heartless Summoning If youre playing big creatures, whats better than paying 2 mana less for each one