I’ve played about 60-70 games with Imperius and tried a few different builds over and over in different situations against different heroes and I have to say that he really does only have one build.
You can variate between the armour reduction, and armour gain on his E charges but that’s it really. His 80 second long skill shot 2 second self stun pales in comparison to the other ultimate. Being able to shield yourself, or use it early to get a guaranteed fast kill someone smashes the finnicky, weak gorge straight off the wall. The AOE shield at 20 on it is the icing on the cake. If it’s even going to compete with the utility and power of shielding and nuking then it’s got to be a lock on ability and make him unstoppable while charging. Otherwise there’s just no contest.
Each talent tier has aclear winner, and using the ‘niche’ picks such as the heal and root break on E often make you play in a way that doesn’t lead to success. For example with this particular talent, say Arthas or malfurion root you during a team fight, you could break the root and continue to pressure, but it’s really easy to focus and nuke Imperius, and you really HAVE to use your E’s self heal wisely or else you’re defenseless. It would be like, if Sonya’s whirlwind had a talent that made her use whirlwind for another thing than its main use. Like no, she needs to use whirlwind wisely to heal herself.
His Q, while satisfying to hit multiple targets, is also very finnicky and I find myself locking down more kills with a quest complete W than I do with the stun on Q. If an ally pushes the enemy you’re stabbing while they are stunned it breaks the stun. If anyone knocks you back it breaks the stun. The stun itself pushes the enemy into a central position at the end of the spear so sometimes, it doesn’t even serve as an effective engage, because the distance they are pushed away negates the duration of the stun.
One thing I think he really needs is something that gives him movement speed. I would take the talent that does this but it relies on a Q, his weakest ability, and is on the same tier as his two most powerful talents by far. 25% damage bonus or 50% damage reduction on his E…
Overall I think he is an average hero, a little lackluster in some ways, can shine against certain comps with no stuns, but as with any hero these days, just spam a couple of stuns on him and you’ll probably interrupt him doing something and put it on a hefty cooldown, and then he’s toast.