Don’t think this was intentional. Combination Mutation of Life Leech + Diffusion makes Melee units almost invincible.
I had 10+ marines shooting at 1 zergling, and it wouldn’t die.
I had a at least 24 marines + 2 elite tanks shooting at Aberration and he’s not losing any life at all.
Yes, I have seen this combination as well. Both the mutators seem to work like intended, but the combination is very bad. You won’t probably see that as a weekly mutation, you’d be wise not to select this combination in Custom game, and if you get it in Brutal+ … then you have to restart I guess (didn’t you know already, that Brutal+ sux?)
IDK, sounds like a fun challenge!