Soul Capture (Custom Gamemode)

Very simple gamemode I thought of while testing my ping in a custom match. Rules are simple, you start off by making the game in a Twisted Treeline match, have 3 people going against 1 thresh. Here are the mechanics/rules:

Thresh:

1. Can't get any summoner spells that give mobility on the field (flash, ghost, heal)
2. Can't use boots of any kind
3. Can respawn without penalty

Other:

1. Can respawn if Thresh doesn't capture their soul
2. While captured, you can only roam the jungle and kill wraiths and wolves, or capture shrines
3. Can't attack Thresh or lane while captured
4. Can only return to the fight if Thresh is killed by another player, while captured
5. Once freed, you must recall and then you can resume laning and fighting
6. Can only level up each skill once

You think this can work? Leave a comment on what would make this a better custom gamemode.