Not gonna lie: Every once in a while, we all get that urge. Throw away all sense of caution, just troll a team, etc. But that's against the rules and hurts other people's enjoyment. So, dear reader, I've found the perfect way to incite anger in the enemy WITHOUT having to do problematic things like troll, feed, taunt or be good at the game.
Be a Hypeman.
Essentially, get into a game and wait for "the moment". The moment is usually when someone on either team starts talking a TON of shit about someone. Usually the victim of said trash talk really didn't do anything bad. The instigator is just hollering and getting pissed. From then on, you have your targets: The one being treated like shit is your hype target while the instigator is your enemy.
Your goal for the rest of the game is to treat the victim as if they're god upon this earth. Lavish praise upon them. Expound upon even the most minuscule of things they get right. _Pretend this man is any competitor MOBA and you're desperately trying to get people to play your game on the League boards_. Likewise, anytime the instigator argues against you, downplay them. They haven't seen a GOOD in action. They just don't understand the intense macro/micro plays your hero is doing. Thank the victim for letting you see what it's like to play with a pro. Some other favorites include:
"Holy shit, this [champ] is such a chad."
"Was that...the REAL [champ] !?"
"Gotta be honest, I've never seen a better [champ] in my entire life."
"Do you main [champ] or are you just that good?"
Eventually, the instigator will get fed up and start attacking you, claiming you're a fanboy or a duo or whatever. You're simply waiting for them to admonish your own skill at which point you direct praise right back to the victim: Yes, you AREN'T that good. This guy is just carrying you. Anything good you've done has been set-up by your champion of champions and you're just along for the ride. At this point the instigator is likely pissed, trying every trick in the book to diminish your or your ally's accomplishments. They'll be tilted. They'll go for hopeless 1v1s against your hero JUST to shut you up. They'll do everything in their power to try and make you see how wrong you are. But you don't care. You're well beyond the point of caring. You're essentially the guy who spent $2000 on Overwatch loot boxes and you're far too deep to ever admit it's a bad game.
By the end of the game, win or lose, the enemy is thoroughly tilted. Hell, they may even turn blame on each other if they lost. At which point you remind them it's not their fault, they just went up a god as mere mortals.
In doing this, you'll rally your team and become a lightning rod for people to hate. Likewise, they can never really counter your arguments or attack you personally, as the person you're hyping up is dead silent or just not doing amazing. Hell, pick your hype target right and you might annoy the enemy so much they start focus-firing the tank or some other non-valuable target JUST to /all you about how easy it was to kill your hero.
Hypeman is environmentally friendly trolling. At it's best, you're making your team happy and inspiring ire in your enemy without any trash talk. At worst, you'll just piss one guy off so much that he'll start targeting you instead of your teammate.