Do all "constant" abilities that affect cards in play happen instantly after step 3? Or are they considered passives that "trigger" off the character coming in to play (during step 4)?

(Examples; Randyl Tarly, Winterfell Castle, Holding the Trident, Threat from the North, etc)

Or, as a specific example, is there ever a moment where Randyl Tarly isn't S4 (barring negative modifiers, of course).

-Istaril said:

No. Constant effects affect the game immediately and continuously.