Magnus + Winter Wyvern

Why this works

Using both ultimates in the same teamfight often creates a conflict. The goal of Reverse Polarity is to group enemies for Magnus and his allies to hit with cleaves and area-of-effect spells. Winter's Curse, however, makes its primary target immune to all damage from Winter Wyvern's team. If Wyvern curses a hero caught in Reverse Polarity, that enemy is suddenly protected from all follow-up, wasting the setup. The damage from the Cursed target's own allies rarely matches the focused burst Magnus enables, making their signature spells work against each other.

This forces the two heroes to play on separate beats. To avoid the anti-synergy, Winter Wyvern has to hold her ultimate during the Reverse Polarity stun or use it on a completely different target, which splits the team's focus. They can try to use their spells sequentially, but this requires perfect timing that is difficult to achieve in a chaotic fight. Even a well-intentioned Cold Embrace can backfire, saving an Empowered carry but preventing them from dealing damage. Because their core abilities don't naturally amplify each other, the lineup can feel disjointed and less effective than drafting heroes with more direct synergy.