Someone Stop My Players

Okay, so a long time ago in a forum not so far away, I posted a story of my one player, running a Dark Souls ripoff named Siegbert, destroying their first boss encounter with 3 nat 20's. Among the various stupidly OP and BS homebrew rules that my players love in my campaign, you can confirm your crits, with the ultimate roll being 3 consecutive 20's for an instakill, regardless of total HP.

Now it was statistically improbable the first time, and we chalked it up as a really lucky and epic moment. Well, the barb just one upped that.

So the party was attacked by an Adult Red Dragon and were getting as good as they got. It was getting ready to fly back to its lair when the barbarian declared wanted to jump onto the dragon now about 50 feet in the air. Normally impossible, but in this particular circumstance it had a pissed off wyvern hanging off its neck (not really doing much more than annoy it). I grabbed my d100 and told him, "On a 95 or higher, you can attempt to grab the wyvern's tail. Otherwise, you miss the grab and wasted your turn."

I rolled a 97, so he could make a hard Acrobatics check off the jump. And he beat it, of course. So he grabs the wyvern's tail in the brief moment it dips low enough and gets whipped onto the back leg of the dragon when it tries to sting it.

So now everyone is freaking out, cause their Barbarian is trapped on a flying dragon who is either A) about to destroy them or B) fly off with the Barb on his leg. Or C) the wyvern will kill the Barb while trying to sting the dragon. Barb's up, I ask him what he does.

He thinks for a moment, then goes "I use that charm I got to climb towards the head and gore it!"

Okay, the charm in question is called a Spidergoat Brooch, and it gives the wearer +10 climb speed. Additionally, if the wearer has 30ft or more in climb speed, they can make a Goring Charge as a bonus action by moving at least 15 feet towards a target. 1d8 + STR, DC save vs prone: pretty simple stuff.

Well, he's a Barbarian, and with Fast Movement he's at exactly 30ft. And the dragon was just long enough that he could activate the charge. Which of course he rolled 3 nat 20's using 2 different dice sets to finish it off.

So this time around it was a 5% chance to even be able to attempt a 20% chance grab, followed up by 3 nat 20's on the second stupidly over leveled boss monster they've faced. Someone stop these players before they use all their luck!