The Steel-type from Space-Time Smackdown can hit for 110 while doing 20 damage to itself, while the Fire-type from Triumphant Light can do 80 for two Energy if it has any damage on it
This creature is great when you have a ton of removal or play it after a board wipe, or if you have many tiny sac fodder creatures
Id much rather have seen this just straight-up give me the five cards for free, or even let me pick three of the five
Added The Great Grady, C.O.R.G.I
That said, there are not all that many different archetypes in black green that want mana creatures except the rock (which is arguably about 6 different archetypes depending on the build) and as Birds of Paradise is a better fixer and ramper the Elves of Deep Shadow are only there to offer redundancy to other better cards
The more the team thought about this, the more they realized that the change had to come from the cards