Vayne Just Crit Me For Over 1200 Damage

Tumble proc at 6 items does that

She... built crit?

/explanation.

Link the match history

Infinity edge passive, critical damage marks, her having high ad, you having low armour (or possibly negative armour after armour reduction from another source, or near 0 from her armour penetration). Might also have been at the same time she proc'ed silver bolts, which does true damage as percent of Max health (not sure if this can crit though).

~150 AD from items, lvl 3 Final hour, lvl 5 tumble, IE crit on a zero armor target. That is without Runes or Masteries taken into account.

What a lot of people don't appreciate about Vayne is that while Silver bolts is nice to have against high armor+HP opponents, she gets a LOT of her damage from the combination of Final Hour and Tumble. With an IE crit, FH+Tumble adds over 260 damage, without the crit it still adds a bit over 100 damage.