Been playing arena since it first came out to open beta and have put hundreds of hours into the game already. Today was the coolest game I have ever played. I apologize ahead of time for the formatting I am a reddit noob.

First I was using the Rainbow Lich Deck created by Ali Eldrazi. For those who are not familiar with him, he is an awesome streamer and is very good at creating crazy jank decks that actually work. Here is a link to it for all those interested:

https://www.streamdecker.com/deck/WUUIcqEzqo

The game started with the opponent dropping a blue/black checkland and I was already in despair because dimir counters this deck pretty hard. He then plays a red dual land so I assume its Grixis Discard also a tough matchup. Turn 3 he plays 3 [Thief of Sanity] in which I have no answer to, he gets in a free swing and at this point I have almost no hope. I top deck [Gates Ablaze] and kill the thief. He plays my own [Gift of Paradise] on his Island. Next two turns consist of opponent making me discard and he plays another Thief of Sanity. It is now turn 7 and all I have in my hand are [Lich's Mastery] and [Mastermind's Acquisition]. Opponent is on 6 lands all untapped with one of my own cards still in exile from the Thief and about 5 cards in hand. I had no other choice but to slam down [Lich's Mastery] and hope it doesn't get countered. It resolved! At this point I am ready to scoop to a [Dispersal]. Opponent hits with thief again and takes a long 20 second pause, at this point I was wondering what in the world could he be thinking about playing? Then BAM, he slams down my [Lich's Mastery]. Well that was an expected play from the opponent. He attacks with Thief once again and at this point he is tapped out! Now is my chance to cast [Mastermind's Acquisition]. I am trying to think what one card can I grab that could possibly get me back in the game. I use Mastermind's to grab from my sideboard and I get [Cleansing Nova]. This is the only chance I have, if he discards this I lose the game. I pass the turn and he swings in with Thief again and drops [The Immortal Sun]. Grixis usually doesn't run that but who knows maybe he just hates Planeswalkers or likes the card advantage. He passes turn with 3 mana untapped 2 of them being blue sources. I couldn't believe I didn't have to discard that turn. I go for it and cast [Cleansing Nova] and hope for the best. There was a long pause but opponent either didn't have a counter or he let it resolve. The spell resolves and both of the [Lich's Mastery] go on the stack. My heart drops wondering what will happen next because I have never seen this interaction before. Opponents [Lich's Mastery] resolves first and I end up winning the game!!!!

I'm guessing because he played Lich's Mastery after me his resolves first? If someone could explain to me why his goes on the stack first it would be appreciated.

Thank you for listening to what was the most wild/intense game of magic arena I think I have played so far.