If my opponent has used Latios GX's "Clear Vision GX" attack, do I get to draw 7 cards if I use Hala?
If you already used your GX Attack before Clear Vision GX, then yes you get to draw 7 cards for Hala. Otherwise no, getting hit by Clear Vision GX doesn't mean you have used your GX attack for the game.
Source: Unified Minds FAQ (2019-07-19), TPCi Rules Team (2019-08-01), TPCi Rules Team (2019-08-29)

Relevant cards

Note: All applicable cards may not be listed below.
SM11_223
SM11_223
SM11_243
SM11_243
SM11_78
SM11_78
SM2_126
SM2_143