I can actually get behind this one. I feel like it should really be tier 3; the damage it does is devastating to low HP units. It wipes any and all infantry way too easily for it's cost.
See, I don't get this about a lot of players here. They see that a leader has one or two things going for them and they want to nerf them. In this case, decimus and vortex.
Once vortex is used and goes on cooldown, what does decimus have? .... exactly. Siphon is alright, killing frenzy doesn't last too long, glassing beam is only decent against infantry, etc.
Decimus has no unit drops and only two leader powers that can cause damage, only one of which is exclusive to him.
Decimus NEEDS that early aggression. It's what made him go from bottom tier to a viable pick. Now that he has presence if doesn't mean we just send him back to where he came from.
It's just a trend I see on the forums. You guys seemingly want everyone to be equally useless whereas the goal should be the opposite. Some leaders excel in the early, mid, or late game. Decimus is early game for one reason - vortex. Take that and he's useless.