Post by piWhat if I have multiple Seedborn Muses in play during an opponnent's untap
step, will I be able to play fast effects between the untaps?
My suspicion is yes, but I'll let an expert confirm that.
Post by piWill I be able
to tap lands between the untaps?
If you can play fast effects you can tap mana sources for them.
If you can't, I'm less sure.
If you can't play fast effects but can tap land them you'll need
to make sure you have something to spend that mana on during the upkeep
phase.
Post by piDoes having multiple Seedborn Muses in play
have any advantage at all?
Well, multiple creatures are often an advantage, both as more attack
options, more blocking options, and lower chance of losing your only
muse.
Post by piI want to know this because I'm curious how much advantage I could get from
a Seedborn Muse imprinted on a Soul Foundry.
Good one.
If nothing else, you'll be able to bring out a new muse after your
old one gets toasted.
Hm, also see if this helps:
303. Upkeep Step
303.1. As the upkeep step begins, any abilities that trigger at
the beginning of that upkeep step and any abilities that triggered
during the turn's untap step go on the stack. (See rule 410, "Handling
Triggered Abilities.") Then the active player gets priority and
players may play spells and abilities.
So, the active player will get a chance to play fast effects.
I'm assuming if he passes, the inactive one does, and that both
get the chance to respond to other triggers and fast effects.
But again, wait for an expert to correct me or agree with me...
Also so definition of priority:
Priority
The player who has the option to play a spell or ability at any given
time has priority. See rule 408, "Timing of Spells and Abilities."
Each time a spell, _an_ability_(other than a mana ability),
^^^^^^^^^^^^
or combat damage resolves, and at the beginning of most phases and
steps,
the active player receives priority. After a player plays a spell,
ability,
or land, or takes a special action, he or she again receives priority.
_When_a_player_passes,_his_or_her_opponent_receives_priority.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
If both players pass in succession, the spell, ability, or combat
damage on top of the stack resolves or, if the stack is empty, the phase
or step ends.
Each time a player would get priority, all applicable state-based
effects
resolve first as a single event (see rule 420). Then, if any new
state-based
effects have been generated, they resolve as a single event. This
process
repeats until no more applicable state-based effects are generated. Then
triggered abilities are added to the stack (see rule 410). These steps
repeat in order until no further state-based effects or triggered
abilities
are generated.
If I'm reading everything right, you're good to go!