When Shen is played at a contested battlefield you are defending, does he enter with 3 might and then gain 2 from Shield (triggering effects that care about units becoming mighty), or does he enter already at 5 might?

Ruling: Shen enters the board with 3 might and then becomes mighty (gaining 2 might from Shield) during the cleanup phase after he resolves. This does trigger effects that care about units becoming mighty.

Sequence:

• Shen is played and resolves, entering the board with 3 might
• During the cleanup phase after he resolves, he gains the defender designation
• Once he has the defender designation, his Shield passive ability activates, increasing his might to 5
• This transition from 3 to 5 might counts as "becoming mighty" for trigger purposes

Nuances:

• There is no window to respond between Shen entering at 3 might and him gaining the defender designation during cleanup, as cleanups do not use the chain and cannot be reacted to
• Players cannot cast damage spells to kill Shen while he is at 3 might because the cleanup happens before any player can react
• This interaction is relevant for cards like Fiora Legend that care about units becoming mighty