Disruptor + Mars

Why this works

Dropping both Arena of Blood and Kinetic Field on the same group of enemies is often a waste. Mars already traps targets inside his ultimate, so adding Disruptor's containment ring on top doesn't add much more lockdown. You're committing two major teamfight spells to do the job of one. This core redundancy is the main reason the pairing struggles. The spells can even work against each other, as the slight knockback from Kinetic Field can push an enemy away from the arena wall, preventing Mars from landing a critical Spear stun.

Throughout the game, this forces an awkward choice during teamfights. Either you stack both ultimates inefficiently, or one hero holds their biggest spell and feels useless. While a good Glimpse can pull an enemy back for Mars to trap, it's a small bright spot in a lane and teamfight plan that feels disjointed. Opponents can often weather the storm because your two biggest control spells don't present separate threats. Instead, they create a single, overlapped zone of control that is easier to play around than two distinct problems.