Mindslaver does not allow control over other player

[ianelletson]

Testing Blue Tron now and rocking mindslaver. I'm able to see my opponent's hand using "Switch Hand" and I'm able to attack with their creatures but I'm unable to tap their lands or play their spells.

Current version of Xmage, Win 10.

[LevelX2]

Closed older duplicates:
#1170
You should be able to see face-down permanents of your opponent if you control him (with Mindslaver for instance). Same applies for face-down cards they can look at.

#1077
Reports:
http://www.slightlymagic.net/forum/viewtopic.php?f=70&t=17295&p=181663&hilit=Mindslaver#p181663
http://www.slightlymagic.net/forum/viewtopic.php?f=70&t=17365&p=182603&hilit=Mindslaver#p182603
http://www.slightlymagic.net/forum/viewtopic.php?f=70&t=17186&p=180311&hilit=Mindslaver#p180311

#1480
https://www.reddit.com/r/XMage/comments/41rc9a/mindslaver_broken/
can confirm there was a older version where mindslaver worked fine now if you control a opponant most of the time you can do stuff :-/

[R1ncewind]

Can confirm that Mindslaver does currently not work as intended.
Also, if you go to your own turn, sometimes your lands are untapped and then, as the notification that you lost control of your opponents turn pops up, re-tapped.
The lands then are untapped again after you pass priority and enter your drawphase, but you can not use them during your upkeep.

[drmDev]

I've had Mindslaver work correctly when I played it a couple months ago so the issue is difficult to duplicate.

[JayDi85]

Fixed in #12878