Hawkeye's Bow + Fatestitcher + Kelpie Guide Combo

All permanents on the battlefield (Hawkeye's Bow attached to either Fatestitcher or Kelpie Guide on the battlefield and Fatestitcher and Kelpie Guide without summoning sickness on the battlefield).

Activate Fatestitcher by tapping it, targeting Kelpie Guide.

If Fatestitcher has Hawkeye's Bow attached to it, Hawkeye's Bow triggers, dealing 1 damage to each opponent.

Resolve the Fatestitcher ability, untapping Kelpie Guide.

Activate Kelpie Guide by tapping it, targeting Fatestitcher.

If Kelpie Guide has Hawkeye's Bow attached to it, Hawkeye's Bow triggers, dealing 1 damage to each opponent.

Resolve the Kelpie Guide ability, untapping Fatestitcher.

Repeat.

Infinite damage