Im more inclined to think the card will be banned than not, but this one could go either way
For example, if you put a Robobrain War Mind onto the battlefield with The Master's last ability, its base power and toughness will be 3/3, and the number of cards in your hand won't affect its power at all
As an attack trigger, it makes me think of Sphinx of Forgotten Lore as more of an aggressive card for playing with combat tricks
The fact that these cards, which are Saga enchantment creatures in the set, use counters themselves made it even more of a perfect fit
The face commander, Neyali, has incredible value for their low cost
If you sacrifice Lucius as the cost for Bone Splinters, its trigger happens while your spell is on the stack