Dual lands (like Hallowed Fountain) are tied to both colors they have mana symbols for, and are only legal if those colors are in your commanders color identity
This section will repeat some of the information above for completeness
Keep in mind, there will probably be a lot of times when it does nothing
I also love this with Hijack effects, steal an artifact or artifact creature, swing or tap, then after combat sacrifice to cast
Against combo decks, being able to evoke Grief then reanimate it back on turn one is sometimes enough to win games on its own
Partner (You can have two commanders if both have partner.) Partner (You can have two commanders if both have partner.) Legendary Creature - Goblin Artificer Tymna the Weaver Lifelink At the beginning of each of your postcombat main phases, you may pay X life, where X is the number of opponents that were dealt combat damage this turn