[CRASH] Picking Yasuo causes game to freeze immediately on loading

Several times recently I have tried to play Yasuo, but every time my game has frozen immediately when champions spawn.

I can easily replicate the bug by picking Yasuo in a custom game. Steps:

1. Create a new custom game
2. Pick any of the following maps: Summoners Rift, Twisted Treeline, Crystal Scar (no crash occurs on Howling Abyss)
3. Fill both teams with bots
4. Lock in Yasuo in Champion Select
5. Wait for loading screen to complete
6. The map loads, champions spawn, but the game is frozen. The clock is blank and you appear to have no gold (instead of 475 or whatever the starting amount is for the given map). The game music and ambient sounds are playing, but the announcer never welcomes you to Summoner's Rift (or tells you if minions are spawning, etc). I am unable to tab away from the game or take a screenshot (sadly), so to fix I must use Ctrl + Alt + Delete (I am on PC) to escape the game, then I can force the game to quit with Task Manager.
7. Log back in to League of Legends and reconnect to the game. The game functions as normal. If you complete all these steps quickly enough you can get back into the game before minions spawn and play normally.

I have also had this experience the last 2 times I picked Yasuo in normal games (so it is not an issue with Custom games).

I wish I could include a screenshot of what the game looks like when it crashes, but my computer will not respond to any commands except Ctrl + Alt + Delete during the crash. The map appears normal, but many HUD items appear weirdly blank (the counters in the top right are all blank except for the global team kill counters, which correctly both read zero). The mini-map is loaded correctly. On Crystal Scar and TT champions spawn correctly, but on Summoner's Rift (beta) only the champion Health Bars are visible -- the actual player models are all invisible, probably because of the nifty new spawning animation that champions have on SR (beta).

TL;DR - I cannot currently play Yasuo without forcing my Client to quit and reconnect.