Oracle + Ursa

Why this works

Thinking False Promise gives Ursa a free pass to go wild is a common mistake. While Oracle can save him from death and use Purifying Flames for a big heal, the execution is often awkward. Ursa's own ultimate, Enrage, already provides massive damage reduction, so False Promise can feel redundant if Ursa could have just saved himself. There’s also the very real risk of Oracle accidentally casting Fate's Edict on Ursa during a fight, which disarms him and makes him completely useless. The synergy has some clear points of failure that make it less reliable than it seems on paper.

Their laning phase together is often difficult, as they don't set each other up for kills very well. Later in the game, their big combo becomes predictable. Enemies learn to kite Ursa and bait the ultimates. A proactive False Promise for a dive is easy for the enemy team to disengage from, putting key spells on cooldown for nothing. The duo relies too much on a single, telegraphed play, and it doesn't fully fix Ursa's core problem of sticking to targets, which is what he usually needs from a partner.