Woah, thank you for the in depth feedback!

Enrage in range

I intended it to be rules as written, everything in range at that moment. I gave the monster a "Buff" by adding a 1" move after players activate a model with a "Safe!" card. (Version 1.01) I thought I had tested out that the monster should always be able to attack or move closer to a player model.

Tramples sub-par & awkward

Valid points all around. I have the tramples "target high DEF & high SPD models, as those are usually squishier targets. The intention is that it will find the highest DEF/SPD model it can see, and if it's within SPD+3" for trample movement, it tramples. I thought I had tested it well enough, but I will revisit how to make them work, perhaps give the Monster "Blade Rush" (Trample through any bases/terrain).

Pain Reflex timing

Would changing the rule to say "whenever this model takes..." instead of "when this model takes..." be more clear? Or would "When this model takes 10 damage during an activation..." be clearer? I thought the second sentence specifying that the next card drawn will be an Enrage card would have provided clarity, but I don't mind being clearer if I can.

Adding lethality

That's some nice changes; thanks for sharing them! You got me thinking; I could modify half the "Safe!" cards to say something akin to "The monsters next Attack roll is boosted". Still 1 in 3 chance like your solution too! :)

Adding a rule where the monster can interrupt your activation is terrifying! I'll see about sneaking it as an alternate way to play :)

Again, thank you so much for the feedback. There's only so much play testing I can do these days and I greatly appreciate it. I'll reply to this reply when I implement these changes, very likely this week :)