Also Grim, you really should write that story up some time, a riptide killing a friggen bloodthirster in MELEE is absolutely hilarious. Have to feel sorry for the poor bastard given the admonishment khorne would be giving them
It was stupid more than anything else.
I charged a Bloodthirster of Unfettered Fury, the vanilla 'thirster basically, into a Riptide with two drones that was trying to hide behind a small patch of trees. The Riptide had overcharged it's reactor to buff it's invulnerable save to 3+ instead of 5+, combined with bad rolls on my part (and forgetting the 'thirster caused Instant Death on 6s to wound) it suffered no real damage in the first round of the assault, the Riptide proceeded to whiff it's attacks back at the 'thirster, and then one of the
drones managed to cause a wound. A drone.
That more or less set the tone for the next few rounds, the Bloodthirster would land a few hits, they'd mostly be saved by a 3+ invun, the Riptide would flail futilely, occasionally landing a hit, and the drones would keep chipping away at the daemon, eventually the Bloodthirster was nudged to death, with the drones causing 3 of the 5 wounds it took over the fight. The riptide and it's drones were then cut in twain by a Bloodthirster of Insensate Rage and it's D-axe that had been making it's way over in 2 or 3 turns (4 to 6 individual rounds) that fight took.
Since then I usually just target the drones first and just chase the Riptide down when it runs, as it usually does. I can't actually remember who won that game though, I think it was a casual doubles match, KDK and Tyranids against Tau and Guard. We were stomping until a Farsight bomb costing about 800 points dropped into my brother's backline and wrecked him with more plasma than I have vehicles. There was so little left by the end of game, I think all they had left was a Valkyrie and the Farsight bomb, I had a Decimator shuffling around, a couple of bloodletters and my brother had a few small 'nids running around.
I do have terrible luck with Bloodthirsters though. In almost every fight mine get into they miss most of their attacks. I once had a vanilla 'thirster and a d-thirster locked in combat with Canoptek Wraiths for the first couple of turns of a game with barely any wounds caused by either side until the d-thirster rolled a bunch of 6s and bisected everything around it.
My best anecdote for Chaos was probably when 5 Possessed and 8 cultists killed two Necron Lords, a unit of 10 Immortals and 3 Destroyers. One of the Lords even had a reanimation orb.